This paper presents the new simulation model for the performance analysis of Surface-Mounted Permanent Magnet Synchronous Motor(SMPMSM) Drive System which is integrated with a controller and a power converter. To enhance reusability and compatibility, the system model is expressed by the association of independent sub-modules reflecting the real physical construction. This concept allows another independent sub-module to be effectively inserted in the model for the comprehensive analysis of larger systems such as a Machine Tool and HEV. The developed model which is composed of MATLAB/Simulink's basic blocks can rapidly analyze not only the entire behavior of system, but also the functional relationship between each components for the effective development of controller.

Miniature BLDC is widely used in industrial applications because of high driving efficiency and high torque characteristic. Otherwise the general BLDC, torque ripple of a high speed miniature BLDC is serous during conduction due to the very low electrical time constant. This paper present instant voltage and current control for torque ripple reduction of a high speed miniature BLDC. Computer simulation and experiment test for 40,000 rpm miniature BLDC show the verification of the proposed control method.

This paper describes a novel sensorless excitation position detecting method of Switched Reluctance Motor(SRM) drive. A suitable excitation pattern of each phases is determined by comparison of detecting current without an inductance estimation. The principle of the rotor position estimation is based on the detection of phase current according to rotor position. This sensorless method is very simple and gives efficient control of drive system. The suggested method is verified by experiments.

This paper is written by research for the transient characteristics of the Single-phase Line-start permanent Magnet. The Single-phase Line-start permanent Magnet is most likely to substitute for Single-phase Induction Motor which is used about many appliance currently, because that has good points. For example, It has a Line-start of ability and a High-efficiency. And it need not power convergence device. The rotor of The Single-phase Line-start permanent Magnet has cage-bar with permanent magnet. This motor is started by cage-bar. When it entered synchronous condition, the rotor is rotated by the permanent magnet. But the design of the permanent magnet is very important, because the breaking torque of the permanent magnet interrupt to start a rotor. Finally, if Flux Barrier is not concerned, we do not get result of our object. Therefore this thesis is concerned about Flux Barrier.

The current unbalance occurs in an induction motor with the supply of unbalanced voltage. Existence of an current unbalance occurs by various problems at the time of driving by in crease of the noise not to mention output decrease of a motor by increase of a loss. We confirmed how current unbalance occurred by a voltage unbalance because a slip came to change by the driving situation of a subordinate as for the induction motor. We confirmed that case to run to a low slip in a ratio of the same voltage unbalance rate brought a high current unbalance rate.

A pulse with modulation(PWM) that keeps a constant angle of dwell and adjust duty ratio is a good method to control a speed of SRM. And a method of one pulse control is proper a operation on range of high speed in SRM for a good energy efficiency. Because PWM method is more safety than one pulse method, conversion of those is best choice according the speed range. So, some algorithm is need for smooth conversion of the mode of control. This paper presents a factor of conversion that proper the conversion of control mode between PWM and one pulse method This factor is from estimation of torque and proper at the variable range of conversion and show the better conversion characteristic than constant factor of conversion.

Different from the conventional motor, the superconducting motor has so large air-gap that the actual parameters such as excitation voltage have considerable difference from the values obtained from 2-dimensional electromagnetic analysis. This paper introduces 3-dimensional EMCH(Equivalent Magnetic Circuit Network) method or FLUX-3D FEM(Finite Element Method) software to reduce the error originated from the 2-dimensional electromagnetic analysis for the development of a 1 MW class high-temperature superconducting motor.

We investigated fault current limitation characteristics of the resistive superconducting fault current limiter(SFCL) which consisted of a Bi-2212 bulk coil and a shunt coil. The Bi-2212 bulk coil and the shunt coil were connected in parallel. The Bi-2212 bulk coil was placed inside the shunt coil to induce field-assisted quench. The fault test was conducted at an input voltage of 200 $V_{rms}$ and fault current of 12 $kA_{rms}$ and 25 $kA_{rms}$. The fault conditions were asymmetric and symmetric, and the fault period was 5 cycles. The test results show that the SFCL successfully limited the fault current of 12 $kA_{rms}$ and 25 $kA_{rms}$ to below $5.5{\sim}6.9kA_{peak}$ within $0.64{\sim}2.17$ msec after the fault occurred. Limitation was faster under symmetric fault test condition due to the larger change rate of current. We concluded that the speed of fault current limitation was determined by the speed of current rise rather than the amplitude of a short circuit current. These results show that the Bi-2212 bulk coil is suitable for distribution-class SFCLs.

The modelling of some different types of switchgears has been reported in the previous papers. This paper consists of two parts. The first part concerns the modelling and simulation of switching arcs with an auto-expansion circuit breaker as an example. The second part focuses on the simulation of the PTFE nozzle ablation effect with three different nozzle shapes. For circuit breakers, the modelling of moving contact and the choice of time steps are discussed before typical results are given and compared with available test result.

자기누설탐상시스템은 지하에 매설된 가스관에서 발생되는 부식이나 크랙 또는 기계적 변형을 탐지하기 위한 방법으로 비파괴검사 방법의 하나이다. 가스관은 Nd자석에 의해 착자가 되고, 가스관에 부식이 발생했을 경우 가스관의 단면적이 작아지게 되어 자기누설이 발생하며, 발생된 자기누설을 홀센서로 검출하여 부식의 유무, 크기, 모양 등을 판별하게 된다. 지하매설 배관은 배관의 직경은 같으나 배관의 두께는 다양하게 존재한다. 특히 30inch의 배관에는 배관의 두께가 11.1, 14.3, 17.5 mm 등이 있다. 자기누설탐상시스템은 배관의 단면적 변화를 감지하는 것이기 때문에 배관의 두께에 따라 그 특성이 변화하게 된다. 또한 두께에 따른 결함의 종류에 따라서 검출신호도 변화하게 된다. 따라서 본 논문에서는 배관의 두께 변화에 따른 검출신호를 분석하였으며, 두께 변화의 영향을 적용하여 검출신호를 보정하기 위한 방법을 제시하였다.

횡자속형 전동기는 3차원적인 자속의 흐름 때문에 기존의 전동기와는 달리 2차원적인 수치해석이 용이하지 않으며 특성 분석에 상대적으로 많은 계산 시간을 필요로 한다. 본 논문에서는 퍼미언스법과 철심의 포화를 고려하기 위한 최소한의 유한 요소 해석을 결합하여 횡자속형 전동기의 특성을 분석하기 위한 해석적인 방법을 제시하고자 한다. 본 논문에서 제시하고 있는 추력 및 쇄교 자속량을 표현하는 수식들은 향후 전동기 제어 알고리즘 개발이나 최적 설계에 응용될 수 있을 것으로 판단된다.

In this paper, magnetic levitation characteristics of hybrid magnets are experimentally shown under the newly proposed airgap condition. The digital PID controller is utilized to control the airgap of the magnetic levitation system.

In this paper, finite element analysis (FEA)-based optimization using Internet distributed computing is proposed for the real world and complex optimization such as optimal design of permanent magnet do motor (PMDCM).

This research presents a topology optimization for manipulating the main heat flow in coupled magneto-thermal systems. The heat generated by eddy currents is considered in the design domain assuming an adiabatic boundary. For a practical optimization, the convection condition is considered in the topological process of the thermal field. Topology design sensitivity is derived by employing the discrete system equations combined with the adjoint variable method. As numerical examples, a simple iron and a C-core design heated-up by eddy currents demonstrate the strength of the proposed approach to solve the coupled problem.

This paper proposes a new linear magnetic damper for absorbing shock from a crash accident involving high speed vehicles. The magnetic damper is composed of a conductive plate, a yoke and permanent magnets which are constructed to a Halbach array to improve the damping force. In order to calculate the damping force, finite element analysis(FEA) using J-Mag, a commercial FEA tool, is performed and the results are validated by the experiment. Also, the design optimization of the plate generating the eddy current causing the damping force performed to obtain the most efficient damping force. Finally, the specifications and the performance of the proposed magnetic damper are represented.

대부분의 초전도 전력기기의 경우, 초전도 테이프를 솔레노이드나, 팬케�� 형태로 권선해서 사용하게 되고, 이러한 경우에는 권선을 구성하는 테이프들에 흐르는 전류에 의해 발생하는 자계는 권선내의 각각의 테이프에 임의 방향의 외부 인가자계로 작용하여 자화손실을 발생시키므로 초전도 코일에서의 교류손실을 평가하고 예측하기 위해서는 임의방향 자장에 의한 자화손실에 대한 데이터가 필요하다. 수직 자화손실에 대한 측정값으로서 임의방향 자장에 의한 자화손실을 알 수 있다면 코일의 교류손실 평가는 훨씬 쉽게 접근할 수 있을 것이다. 본 논문에서는 측정된 자화손실 값들로부터 각 방향 인가자장에 의한 자화손실과 인가된 자장을 분리하여 수직방향 및 수평방향 성분에 의한 자화손실 측정값의 합과 비교하여 각도별로 두 자화손실의 차이를 살펴보았다.

Recently, the micro on-off valves have been focused on core technology in the fields of the production line of semi-conductor chips and the micro fluid chips for bio-medical applications. A key characteristics for micro valve, operated by compressed air, are high speed response and great repeatability. Indeed, it is also important to keep the pressure on the cross-sectional area of the poppet to be constant regardless of the fluctuation of the pressure exerted on the ports. In this study, we have designed and analysed the high-speed and high flow rate micro on-off valve using the analogy of equivalent magnetic circuit and Finite Element Method(FEM) respectively. In case of poppet, flow field characteristic was analyzed by the variation of poppet and it was able to display flow field by changing the location of the poppet. Also, we verified possibility of the design through the static and dynamic pressure and the 3D distribution curve of the force by working the front poppet.

전기기기에서의 전자기력 계산은 기기의 성능뿐 아니라 기계적 변형, 진동을 예측하는 주요 파라미터이다. 지금까지는 Maxwell stress tensor법이나 자하법, 가상변위법등에 의해 전체 전자기력 또는 토크를 계산하여 왔으나, 이 방법들은 모두 분포 전자기력을 계산할 수 없었다. 본 논문에서는 기기 내부의 체적 전자기력분포를 계산하는 방법을 제시하고, 그 예로써 영구자석형 전동기의 전자기력 분포를 보여준다. 체적력의 계산은 저자에 의해 제안 된 가상공극법에 기반하여 구현할 수 있다.

On the contrary of a conventional motor with very narrow air-gap, it is difficult to calculate the accurate magnetic field distribution and the performance of an air-cored superconducting motor by 2 dimensional analysis, which does not use high permeability material except outer machine shield. This paper aims to do analysis of magnetic field and force distribution from the 3 dimensional modelling of a 1MW class superconducting synchronous motor. Especially, the field coil composed of Bi-2223 high-temperature superconductor and the outer machine shield are modelled by finite element analysis software according to their structures and the self-inductance and Lorentz force are calculated based on the 3 dimensional magnetic field calculation.

최근에 모터제조 산업계에서는 국제시장에서 동 가격(Copper Cost)이 급격히 상승함에 따라 자연히 알루미늄 코일의 사용에 대하여 더 많은 관심을 갖게 하고 있다. 이는 알루미늄 도체 코일이 동선 코일에 비해 연성이 낮아 모테 권선작업 중에 자주 끊어져 제조상에 어려움은 있기는 하지만 모터 제조원가를 절감하려는 산업계의 피나는 노력에 비추어 볼 때 많은 관심을 불러일으키기기에 충분하다. 본 논문은 산학협력 프로그램의 일환으로 모터 설계 컴퓨터 도구를 이용하여 기존 동선 코일을 사용한 모터와 새로운 알루미늄 코일을 사용한 모터의 성능을 비교하여 교류 전동기에서 알루미늄 코일의 적용 가능성에 대하여 고찰한다.

BLDC 모터는 전자적인 스위칭에 의해 전류(轉流)가 수행되므로 정상적인 동작만을 고려하여 모터 드라이버를 설계한 경우에는 초기 기동에 실패하는 사례가 빈번히 발생한다. 그 원인은 대개의 참고문헌이나 기술자료에서 초기 기동에 관한 요구사항은 찾아보기 매우 힘들고 전자부품의 특성상 사용자는 제조자가 서로 다른 다수의 부품을 조합하여 회로를 구성해야 하기 때문이다. 본 논문에서는 저자가 경험한 개발 사례를 중심으로 초기 기동실패의 원인분석과 그 해결책을 소개한다. 논문의 지면관계상 구체적인 이론에 근거한 기술보다는 회로설계에서 경험하는 실용적인 노하우를 중심으로 간추려서 소개한다.

최근 반도체산업과 광산업 분야에서 고정도의 위치제어 및 고출력 구동이 가능한 초음파 리니어 모터에 대한 관심이 증가되고 있다. 저자는 공진시스템으로 지지하는 고출력 초음파 리니어 모터를 제안해왔다. 이 모터 시스템은 주목할만한 동작 안정성과 제어능력을 달성 하였지만 모터의 공진 주파수가 예압, 열등의 외부의 요인에 의해 변하게 될 때, 모터는 공진 시스템에 의한 지지 메커니즘이 고정된 공진 주파수만을 가지게 되어 안정적인 구동을 이루기 어렵게 되었다. 본 연구는 고강성 지지를 위해 한 진동자에 세 지지점을 가지는 새로운 모터를 설계 하여 시스템의 위치제어 능력에 대해 조사 하였다. 고강성을 띄는 세점 지지부는 모터를 확실히 지지 할 수 있지만, 진동 모드에 영향을 미치지 않는다. 20 mm의 지름을 가지는 모터를 이용하여 기계적 최대 출력은 75N, 무부하 최대속도 0.45 m/s를 달성하였다. PID 피드백 제어 시스템을 적용시켜 6 kg의 스테이지를 100 nm의 정도를 가지고 200 mm/s로 위치 제어를 달성하였다.

This paper deals with the optimum rotor design solution on torque ripple reduction for a SynRM with concentrated winding using response surface methodology (RSM). The RSM has been achieved to use the experimental design method in combination with finite element method (FEM)and well adapted to make analytical model for a complex problem considering a lot of interaction of design variables. Comparisons are given with characteristics of a SynRM according to flux barrier number, flux barrier width variation, respectively.

Recently the development of small hydropower generation with using water pipes is revitalized by the water works facilities. However, when the tubine generator is in case of emergency stop by the internal and external accidents, it causes water hammer in water pipes and suspension of water supply. To prevent these problems of small hydropower generator, we has analyzed water supply patterns, installation position and water pipe systems.

This study investigates the dynamic characteristics of Synchronous Reluctance Motor (SynRM), with segmental rotor structure, using finite element method in which the moving mesh technique is considered. The focus of this paper is the sensorless vector control parameters estimation of SynRM under saturation and iron loss. Comparisons are given with dynamic characteristics of normal single B-H nonlinear solutions and those of proposed FEM & Preisach model of synchronous reluctance motor, respectively.

This paper shows the temperature rise of the high voltage GIS bus bar. The temperature rise in GIS bus bar is due to Joule's losses in the conductor and the induced eddy current in the tank. The power losses of a bus bar calculated from the magnetic field analysis are used as the input data for the thermal analysis to predict the temperature. The required analysis is a couple-field Multiphysics that accounts for the interactions between three-dimensional AC harmonic magnetic and fluid fields. The heat transfer calculation using the fluid analysis is done by considering the natural convection and the radiation from the tank to the atmosphere. Consequently, because temperature distributions by couple-field Multiphysics (coupled magnetic-fluid) have good agreement with results of temperature rise test, the proposed couple-field Multiphysics technique is likely to be used in a conduction design of the single-pole and three pole-encapsulated bus bar in CIS..

Pressure risc is an important design factor and affects significantly on the characteristics of gas circuit breakers. For self-blast circuit breakers, the nozzle ablation plays important role in pressure-building up and should be properly considered for the accurate calculation. In this paper, the nozzle ablation is treated as a boundary condition and the pressure is calculated from mass fractions of PTFE and SF6. The amount of the ablated mass of a nozzle is assumed to be proportional to the are energy and the area of nozzle surface that directly touches arc. The calculation result is compared with measured data and shows good agreement with it.

Various different types of joining between High Tc superconducting(HTS) tapes were prepared and current-voltage(I-V) characteristic curves were investigated at 77 K, liquid nitrogen temperature. Two typos of HTS tapes wore used, one is no laminated tape(Sumitomo high strength type tape) and the other stainless steel laminated tape(AMSC(American Superconductors Inc.) 3ply tapes) Sample joints were lap-jointed with indium or solder. Joint resistances between Sumitomo tapes with 4-10 mm in length were estimated from I-V curves and in the range of $4-8n{\Omega}$ at 77 K. Joint resistances of AMSC tapes were in the range of $140-170n{\Omega}$, much higher than them of Sumitomo samples. The n-values of jointed HTS tapes were 50% of them with no joint. In AMSC tapes, indium is better than solder as the jointing material.

This paper deals with the preliminary study on the HTSC levitation magnet for MAGLEV operating in persistent current mode (PCM). The high temperature superconducting (HTSC) levitation magnet consists of two single-pancake type coils wound with Bi-2223 wire and a persistent current switch (PCS). The levitation magnet was designed by using 3-D finite element analysis. The suspension system for high-speed electrodynamic suspension (EDS) maglev should operated in persistent current mode. It is important to develop a technology to minimize the joint resistance of splice between two HTSC wires. The PCS was observed with respect to various magnitude of charging current. Based on these results, the levitation system using HTSC wire will be further studied.

It is necessary to modify the state-of-the-art of speed control theory because of the phase asymmetry in the Linear Induction Motor (LIM)and for the constant speed control of mover using single vector control inverter system, it is important that primary stack is located in appropriated intervals in the 3D conveyer system using LIM. The dynamic characteristic analysis method of the vector controlled LIM using coupled FEM and control algorithm taking into account the movement is proposed. The focus of this paper is the analysis relative to selecting primary stack intervals in order to constant speed control in the 3D conveyer system using LIM.

The excitation system of 500MVA short-circuit generator is very important because of operation of various condition, for example, (over) load switching, short-time current, short-circuit current, etc. This paper introduces a feature of excitation system of 500MVA short-circuit facilities and the function and construction of each part.

DC솔레노이드 밸브의 성능을 나타내기 위해 여러 가지 중요한 파라메터들이 존재한다. 최소 혹은 최대 스트로크 시의 흡입력, 온도상승, 소비전력 그리고 동작시간 등이 있다. 본 논문에서는 동자시간을 최소화시키기 위해 반응표면법을 이용하여 DC솔레노이드 밸브의 형상 최적화를 수행하였고 그 결과를 유한요소법을 이용하여 검증한다.

The development method of a pneumatic solenoid actuator which is used as key components in automobile and aircraft industry is described. For the optimal design of solenoid actuator, we applied the general electromagnetic theory and empirical knowledge. By using the governing equation for the solenoid actuator based on the electromagnetic theory and empirical coefficient, and constrained of optimization technique, we proposed the optimal design technique of low consumption type DC solenoid actuator. The design results of the DC 24V, 0.5W solenoid actuator were presented.

The electromagnetic pump can transfer molten metals by the electromagnetic force of LIM for molten metals, which are zinc, tin and aluminum. The speed and quantity of the flow are analyzed using magnetohydrodynamics. The molten zinc is used in the experiment and the experimental results are compared with the analysis.

In order to develop a high temperature superconducting(HTS) coil for the fault current limiter(FCL), the over-current characteristics in YBCO coated conductor(CC) with Ni-W alloy substrate are analyzed. The HTS wire is wound by bifilar winding method for resistive current limitation and it is operated in 65K sub-cooled nitrogen. In order to analyze the resistance and the temperature characteristics of the CC wire, an analysis program is developed considering all the composition materials except the buffer layer. Using this program, the temperature rise, the resistance development and the current limitation of CC are calculated depending on the applied voltage and the stabilizer materials. According to the analysis results, under the temperature restriction of 300K, the maximum voltage per meter is determined as 40V/m if the stabilizer is $25{\mu}m$ thick stainless steel at each side. Finally, the wire length needed for the distribution level HTS FCL is estimated.

The inrush current of transformer cause saturation effects of recovery voltage for short-circuit power testing. the inrush current depends on the residual flux of the transformer core. when inrush current occurs, it is contains a d.c. component and the high harmonic content of the current are of importance to relay protection of testing circuit. this paper describes of decrease method of inrush current for high power short-circuit testing transformer.

고온 초전도 선재는 자장의 세기, 방향 그리고 온도에 따라 임계전류가 달라지는 특성이 있다. 임계전류가 달라지는 특성은 초전도 선재를 사용하는 초전도 기기에 매우 영향을 미치게 된다. 자장의 세기, 인가 방향이 선재의 임계전류에 비치는 영향에 대하여 알아보기 위하여, prototype magnet을 제작하고, 선재에 전압 tap을 부착하여 실험을 하였다. 자장의 세기와 고온 초전도 선재가 받는 자장의 방향을 변화시켜가며 실험을 하였다. 또한, 주파수에 대한 선재의 영향을 알아보기 위하여, 주파수 변화에 따른 선재의 임계전류 변화도 측정을 하였다. 본 논문은 고온 초전도 선재를 이용하여 제작하게 되는 고온 초전도 기기 설계의 기초자료로 활용될 수 있을 것이다.

고온 초전도 전력케이블의 통전용량 산정은 먼저 고온 초전도 전력케이블의 임계전류를 먼저 알아야 한다. 선재의 임계전류를 알고자 하는 경우, 전압-전류를 측정하거나 온도를 측정하는 방법을 통해 임계전류를 알아내지만, 고온 초전도 전력케이블의 경우 이러한 방법으로 임계전류를 알아내는 것이 불가능하다. 본 논문에서는 고온 초전도 케이블에 사용되는 선재에 대한 임계전류를 측정하고, 전자장 해석을 한 후, 실험결과와 해석 결과를 토대로 고온 초전도 전력케이블의 임계전류를 계산하였다. 이렇게 계산된 임계전류를 이용하여 고온 초전도 전력케이블의 통전용량의 기초자료로 활용토록 하였다.

A novel control strategy for the induction motor drive, based on the field acceleration method, is presented. The torque is controlled through variations of the stator flux angular velocity. The stator flux is controlled by using a feed forward control scheme, with the stator flux reference vector adjusted so as to obtain the fixed rotor flux amplitude.

본 논문은 슬립 주파수형 벡터제어에 기초하여 인버터 구동 교류 서보전동기 속도제어 시스템을 구성하고 광범위한 속도제어 방법에 대하여 나타내었다. 구동 시스템은 16비트 CPU(V50)을 이용한 디지털 제어기와 전동기 구동 전원으로 순시전류 추종방식 인버터(Current Source Inverter)로 구성된다. 실제 300[W] 유도전동기의 저속에서 속도 변동(진동)이 발생하는 원인을 해석하기 위해서 회로 동작을 소프트웨어와 하드웨어적으로 조사한다. 시뮬레이션을 하여 저속에서 속도변동 원인을 구명하고 그 대책에 대하여 나타내었다.

Generally Short Circuit Test of transformers are tested according to IEEE std C57.12.00-2000, IEC 60076-5(2000-07), ES148(1998.6.26) or KS C4309(2003). But ES148(1998.6.26) is same as IEEE std C57. 12.00-2000 and KS C4309(2003) is revising coincidence with IEC 60076-5(2000-07). On this study condition of the transformers before short circuit test, calculation method for test current peak value, tolerance on the asymmetrical peak and r.m.s value, short circuit testing procedure, number of short circuit test, duration short circuit test, and detection of faults and evaluation of short circuit test result will be compared with ANSI and IEC.

This paper provides the design of propulsion system for the catenary-pantograph run tester. Permanent magnet linear synchronous motor design suitable for an high-speed ground transportation system which need a big acceleration force. The propulsion system of the catenary-pantograph run tester need high speed and big acceleration.

This paper deals with an automatic rotor design functional standard computation based on torque/volume for a synchronous reluctance motor (SynRM). The focus of this paper is the design relative to the torque/volume on the basis of each rated watt according to the rotor diameters of a SynRM. The coupled finite elements analysis (FEA) & sequential unconstrained minimization technique (SUMT) have been used to evaluate design solutions. The proposed procedure allows to define the rotor geometric design function according to the rotor diameter and rated watt starting from an existing motor or a preliminary design.

For the application of superconducting fault current limiters(SFCLs) to the protection system, quench recovery characteristics of Au/YBCO thin film were investigated. The Au/YBCO thin film was designed as a SFCL element with a bi-spiral pattern. The SFCL element limited the fault current successfully. For the analysis of the recovery to superconducting state, we measured resistance variation of the SFCL element after the quench. In addition, in order to investigate the dependence of quench characteristics of SFCL on the $LN_2$ cooling condition, we measured the recovery time under a pressure of 1, 2 and 3 atm. As the results, the recovery time increased in proportion to the duration of the fault currents. In the sub-cooled condition, while the quench development was exactly the same, the recovery time was shortened as the pressure increased.

$SF_6$ 가스절연 Recloser는 선로에 일시적인 과전류가 발생하면 개방 후 자동 재투입 하면서 선로의 정상적인 운전상태를 회복하고, 영구 고장 시에는 정해진 Sequence에 따라 개방, 투입을 반복한 후 개방완료 상태에 이르게 하는 보호기기이며, 조작부는 주로 Solenoid Actuator 방식을 채택해왔었다. 그러나 Solenoid Actuator 방식은 구조가 복잡하고 부품수가 많은 단점이 있어 최근에는 사용 부품수를 획기적으로 감소 시키고 조작 신뢰성을 증대시킨 Magnetic Actuator 방식을 채택하여 사용하는 경향을 보이고 있다. 이 Magnetic Actuator 방식은 구조가 간단하고 부품수가 적어 높은 신뢰성을 확보할 수 있고 유지 보수가 거의 필요하지 않는 장점을 가지고 있다. 이에 본 논문에서는 $SF_6$ 가스절연 Recloser의 조작부에 Magnetic Actuator 방식(이하 PMA (Permanent Magnetic Actuator))을 채용 하였으며, 이를 적용하기위한 입력전원 및 투입, 개방 코일을 패러미터로 하여 PMA의 동적특성을 실험하였으며, 이 실험 자료에 근거하여 27[kV] $SF_6$ 가스절연 Recloser의 PMA 조작부를 설계 및 제작하였다.

Nowadays, research of EMI/EMC is very important in electromagnetic wave surroundings generated from many electric and electronic devices. Especially, analysis of electromagnetic radiation characteristic and field have to be performed first of all. At the present most of EMI/EMC problems are solved by the method of practice and inspiration. Hence in this paper, will provide the first step for solving EMI/EMC problems in design process. Model of analysis is structure composed of PCB and Frame. By the first step, theory of dipole antenna is adapted to analyze electromagnetic radiation characteristic and field. Because it is fundamental of analysis of electromagnetic radiation. And it will be expanded for structure of PCB and Frame. Finally, it provide the basic method of analysis of electromagnetic radiation characteristic and field by making similar dipole antenna to PCB and Frame structure.

최근 저압 기중차단기(ACB, Air Circuit Breaker)는 고압중전기 공인시험제도 및 저압전기기기 안전인증제도와 같은 강제인중 대상에서 제외되어 해당 성능에 대한 안전 사각지대에 놓여있다는 지적을 받아왔다. 본 논문에서는 현재의 ACB관련 규격 및 성능평가기술을 분석하고, 국제규격과의 비교 분석을 통하여 국제규격에 준하는 성능평가기술 및 규격을 제시하는 방안을 연구하였다. 특히 내년에 제정이 논의되고 있는 ACB관련 KS 규격의 제정 방향 및 KS 심사기준에 대한 진행방향 설정과 연구되어야할 성능평가기술을 제품성능 특성별로 제시하였다. 향후 본 논문의 성능평가기술 및 제안 방향이 KS규격 제정 및 활용에 중요한 근간을 제공할 것으로 기대한다.

In the mechanical system, optimization of motion control is very essential in the aspect of automation technique progress. In the servo system, the function of controller is very important but most of the controllers have played only the role of pulse generator because the controller with main function is very expensive. In this thesis, the system was composed of PC, commonly used driver AC servo motor and a produced control board. The PC transmit a gain, a locus data to a driver and controller. At the same time, it converts imformation from the controller and convert them into data and offer an output with graph. The role of a controller is to trasmit a locus data to a driver and counting the pulse on the phase of an encoder to the PC. We have performed the experiment in order to confirm with variable PID parameter capable of the optimization of gain tuning with the counting of feedback control sensor signal with regard to the external interface into the system, such as torque. Based on the experiment result, we have confirmed as follows: First, it was confirmed that we could easily input control factors P.I Gain, constant $K_P,\;K_I$ into PC. Second, not only pulse generator function was possible, but with this pulse it was also possible to count using software with PIC chip. And third, using the multi-purpose PIC micro chip, simple operation and the formation of small size AC Servo Controller was possible.

Industrialization and technique consequently in quick development the motor field small size and light weight, high efficiency and highly energy density in necessity. The permanent magnet motor small size and the research regarding the research of the torque and efficiency is coming to be active. From this paper the research regarding the quality permanent magnet motor and analysis and it was developed recently the NdFeB anisotropic bond magnet which is a high magnetic force material use, from the hazard which accomplishes power density it is high permanent magnet motor of small size and light weight it researched. The Finite Element Method it led and motor optimization. Also the experiment and analysis permanent magnet motor it is improved the motor and result it led and different it compared.

In this study, superconducting coil arrangements and cryostat concept design were conducted for the development of 13.2kV/630A bifilar winding type high temperature superconducting(HTS) fault current limiter(FCL) with YBCO coated conductor(CC) wire. The coil consists of several layers with unique non-inductive solenoid winding method. Six types of HTS coil arrangements were investigated for the optimal insulation design of HTS FCL. And, conceptual design of cryostat was conducted for the decrement of thermal invasion and the prevention of low voltage insulation breakdown in the LHe which is used as pressurization gas in sub-cooling condition of liquid nitrogen(LN2). As the results, it was found that the modified suspended type cryostat with horizontal coil arrangement is beneficial to the insulation design of 13.2kV level bifilar winding type HTS FCL.

In large scale superconducting rotating machine, HTS field coils are constructed with many stacks of single or double pancake coils connected in series. In spite of its higher thermal stability, HTS field coil experiences some quench, which results in some part of burn-out in the field coils. Thus in the view point of the HTS rotating machine field coil design and testing, it was very important to predict the possibility of quench occurrence in the designed field coils. In this paper, a HTS racetrack coil constructed with two single pancake coils and one double pancake coil was tested in LN2 and cooling by GM refrigerator. It is wound using the Bi-2223 tape. The experimental details and results are presented in this paper.

This paper is proposed robust control based on the vector controlled induction motor drive with adaptive fuzzy learning control(AFLC). The fuzzy logic principle is first utilized for the control rotor speed. AFLC scheme is then proposed in which the adaptation mechanism is executed using fuzzy logic. Also, this paper is proposed estimation of speed of induction motor using ANN Controller. The error between the desired state variable and the actual one is back-propagated to adjust the rotor speed, so that the actual state variable will coincide with the desired one. This paper is proposed the analysis results to verify the effectiveness of the new method.

The paper is proposed maximum torque control of SynRM drive using adaptive fuzzy neural network(A-FNN) controller and artificial neural network(ANN). For each control mode, a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. The proposed control algorithm is applied to SynRM drive system controlled A-FNN and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the A-FNN and ANN controller.

The paper is proposed maximum torque control of IPMSM drive using adaptive learning mechanism-fuzzy neural network (ALM-FNN) and artificial neural network(ANN). For each control mode, a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. The proposed control algorithm is applied to IPMSM drive system controlled ALM-FNN and ANN, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the ALM-FNN and ANN.

In this parer, characteristics of the flexible rail in levitation control system are analysed. The magnetic levitation system is an electromagnet type and is full-scaled vehicles. The system consists of electromagnet, chopper, flexible rail, secondary suspension system and levitation controller. The mathematical modelling for the whole system is carried out. Especially, the flexible rail is modelled using second-order mass-spring-damper system. Using the derived model, the dynamic characteristics for the system are presented with different vehicle speed.

In this paper, the characteristics analysis results of the levitation controller of magnetically-levitated vehicle are presented. To get a good closed-loop system, the observer and controller must be designed to meet the control performance and ride quality requirements. So the transfer functions of the observer filter are described and analysed by using the relative and absolute signal concepts.

This paper is proposed hybrid artificial intelligent controller for high performance of induction motor drive. The design of this algorithm based on fuzzy-neural network controller that is implemented using fuzzy control and neural network. The control performance of the hybrid artificial intelligent controller is evaluated by analysis for various operating conditions. The results of experiment prove that the proposed control system has strong high performance and robustness to parameter variation, and steady-state accuracy and transient response.

According to the rapid growth of high speed and precise industry, the application of synchronous motor has been increased. In the application fields, the large synchronous motor is not a self-starting motor. The rotor is heavy and, from a dead stop, it is impossible to bring the rotor into magnetic lock with the rotating magnetic field for this reason, all synchronous motor have some kinds of starting device. A simple starter is another motor which brings the rotor up to approximately 96 percent of it synchronous speed. The starting motor is disconnected and the rotor locks in step with the rotating field. The more commony used starting method is to have the rotor to include a squirrel cage indution winding. This indution winding brings the rotor almost to synchronous speed as an induction motor. So, this paper describes excessive condition interpretation of a exciter circuit to prevent starting failure of large synchronous motor. the large synchronous motor needs safety of it in accordance with operating frequent start and stop. the operating Problem point of synchronous motor appears potential element damage of Exciter circuit because synchronous motor is caused synchronous separation. hence we eliminate it and improve starting toque.

This paper deals with an efficient superconducting joint method between 2G high superconducting(HTS) wire, YBCO coated conductor(CC). Recently CC is one of the most promising superconducting wire due to high n-value and critical current independency from external magnetic field. It is expected to be used many superconducting application such as fault current limiter, persistent current system and cable etc. In most HTS applications, superconducting magnet is used, and it is necessary to joint between superconducting wire to fabricate superconducting magnet system. A CC tape used in this research consists of copper stabilizer, silver layer, YBCO layer, buffer and substrate. Direct joint using soldering method was inefficient due to resistance of copper, then copper lamination is removed by chemical etching method to reduce resistance between CC tapes. Jointed tapes were fabricated and tested. Transport current through jointed area and induced voltage were measured to characterize the I-V curve. Resistance between CC wire using chemical etching was compared with resistance of direct jointed tapes using soldering method in this paper.

This paper is proposed an efficiency optimization control algorithm for a synchronous reluctance motor which minimizes the copper and iron losses. The design of the speed controller based on adaptive fuzzy-neural networks(AFNN) controller that is implemented using fuzzy control and neural networks. The proposed algorithm allows the electromagnetic losses in variable speed and torque drives to be reduced while keeping good torque control dynamics. The control performance of the hybrid artificial intelligent(HAI) controller is evaluated by analysis for various operating conditions. Analysis results are presented to show the validity of the proposed algorithm

The purpose of this paper is to discuss the reasons creating the difference between inductances calculated and measured in the interior permanent magnet synchronous motor designed for the traction. Moreover, the method applied to estimate the inductance is introduced in this paper.

본 연구에서는 전력계통에서 발생되는 surge나 고장전류에 의해서 변압기의 1차측 코일에 유도되는 전자력의 크기를 유한요소 전자계해석 프로그램(FLUX2D)을 이용하여 해석하였다. 400kVA, 6600/220(V) 단상내철형 변압기의 권선간 전자력계산을 축대칭FEM을 이용하여 각방향의 전자력을 분석하였다. 누설자속분포, 전류유입시 권선 상호간에 작용하는 힘의 변화와 힘의 분포, 전류유입시 권선 상호간에 작용하는 힘의 변화와 힘의 분포, 변압기 내부권선의 정상시와 고장전류시의 전자계비교를 전자계해석을 통하여 변압기에 미치는 영향을 해석하였다. 변압기에 대전류가 유입되는 경우의 전자력 분석결과는 변압기의 절연설계 및 단락기계력에 대한 프레임 구조 설계를 위한 자료로 활용된다.

대용량 BLDC 모터의 진동과 소음의 원인은 영구자석과 슬롯형상에 의한 코깅토크와 전류 파형에 의한 고주파이다. 특히 대용량 BLDC의 경우 코깅토크에 의한 진동 및 소음의 영향이 상대적으로 큰 값을 가지게 되며, 본 연구는 5MW급 연구자석형 전동기에서 코깅토크 발생원인 중 하나인 영구자석의 형상을 최적화하기 위하여 RSM(Response Surface Method)과 민감도기법을 적용하여 코깅토크 저감을 위한 연구를 하였다. FEM에 의해서 자속밀도분포와 토크를 계산하고, 1개의 목적함수와 3개의 설계변수를 설정하여 최적화 하였다. FEM과 최적화기법(RSM+민감도기법)을 결합하여 영구자석의 형상을 최적화한 결과 코깅토크의 ripple이 최대 20%정도로 감소되었으며, 목적함수와 설계변수의 개수에 따라 더욱 개선될 수 있다.

최근 전력용 변압기의 고효율, 소형화 추세에 따라 권선의 단위면적당 열발생률이 증가하고 있으며 이는 변압기의 수명과 단락사고에 직결되는 중요한 문제로 대두되고 있다. 본 논문에서는 단순화한 2차원 전력용 변압기 모델의 계산 시간을 줄이기 위해 복합격자(Hybrid mesh) 생성기법을 적용하여 모델링하고 유한요소법을 이용한 자계해석으로 권선과 철심의 Joule's loss를 계산하였다. 계산된 열원으로 전력용 변압기의 최고점의 온도와 열적 특성을 파악하고자 CFD algorithm을 이용하여 변압기 내부의 온도분포를 예측하였다.

In case of the synchronous reluctance motor, the torque is proportional to silency difference and the power factor is in proportion to silency ratio. This paper presents the rotor design variable that has a effect on silency difference and silency ratio for getting a maximum torque and a power factor in the synchronous reluctance motor. To carry through the object, a number of the analysis model is reduced by DOE (Design of Experiments) and the main effects are found by the FEM (Finite Element Analysis).

This paper presents the temperature distribution of the oil-immersed self-cooled transformer with radiator performed by coupled magneto-fluid-thermal analysis. Particularly, 3D temperature distribution of cooling oil and sub-components under the natural convection is obtained by computational fluid dynamics analysis, while heat sources are predetermined by magnetic field analysis using F.E.M. The predicted temperature distribution of the power transformer model is compared with the measured data for verifying the validity of the proposed analysis.

The research is being made on the oncoming generation hybrid EV and FECV in view of energy efficiency and environment. In the future the research will be addressed on the automobile electromotive compression motor and driver which have important competitive points. In this paper, a new method that can presume location of the BLDC Moto rotor of electromotive compressor was proposed, the driver of BLDC motor was made and the possibility that it can be used in the air compressor of EV was proved.

In this paper proposed to Neural network PI self-tuning direct controller using Error back propagation algorithm. Proposed controller applies to speed controller and current controller. Also, this built up the interface environment to drive it simply and exactly in any kind of reference, environment fluent and parameter transaction of BLDC motor. Neural network PI self-tuning simulator using Visual C++ and Matlab Simulation is organized to construct this environment. Built-u-p interface has it's own purpose that even the user who don't have the accurate knowledge of neural network can embody operation characteristic rapidly and easily.

A number of techniques have been developed for estimation of speed or position in motor drives. The accuracy of these techniques is affected by the variation of motor parameters such as the stator resistance, stator inductance or torque constant. This paper is proposed a neural network based estimator for torque and stator resistance in IPMSM Drives. The neural weights are initially chosen randomly and a model reference algorithm adjusts those weights to give the optimum estimations. The neural network estimator is able to track the varying parameters quite accurately at different speeds with consistent performance. The neural network parameter estimator has been applied to slot and flux linkage torque ripple minimization of the IPMSM. The validity of the proposed parameter estimator is confirmed by the operating characteristics controlled by neural networks control.

In this paper, optimized model was designed for the starting characteristic of the Single-Phase Line-Start Permanent Magnet Synchronous Motor by using the Design of Experiment. A field pole angle, thickness and distance from center axis of permanent magnet were selected as design factor. We executed the transient state characteristic analysis of 8 test models. The transient state characteristic analysis was executed by using the 2 dimensional Finite Element Method and the Time Difference Method. We checked the fact that the selected design factor affected starting characteristic of the Line-Start Permanent Magnet Synchronous Motor. Depend on this result we found the optimized design point by using the response optimization.

Interior Permanent Magnet Synchronous Motor(IPMSM) have many advantages such as high power density, wide speed range and so on. With the IPMSM, miniaturization and energy efficient design can be achieved in comparison with Surface Permanent Magnet Synchronous Motor(SPMSM). In order to secure miniaturization and manufacturing efficiency of the motor, it has concentrated winding, because concentrated winding can reduce the motor volume and make manufacturing to be simple compared with the distributed winding. However, according to the pole-slot combinations motor parameters can be changed and unexpected normal force can be generated. Especially, unbalanced normal force in airgap can cause serious vibration and acoustic problem. Accordingly, in this paper, normal force and parameters variation of concentrated winding IPMSM are investigated according to the pole-slot combinations.

Cogging torque is produced in a permanent magnet machine by the magnetic attraction between the rotor-mounted permanent magnets and the stator. It is an undesired effect that contributes to the machines' output ripple, vibration, and noise. This paper presents the stator design for reducing cogging torque in the BLDC motor by using the DOE(Design of Experiments). The cogging torque is computed by using a two-dimensional finite element analysis.

This paper proposes the design method of a magnetic suspension that can control external vibration caused by low frequencies on the external vibrations by low frequencies. The magnetic suspension with individual controls is able to compensate the vibrations unlike a mechanical suspension. In the magnetic suspension, two characteristics are required. Firstly, magnetic motive force(MMF) by armature winding must be increased linearly. Secondly, identical magnitude of output force should be produced as direction of MMF. In this paper, axis-symmetric finite element analysis is used for magnetic field analysis. In order to optimize magnetic suspension, response surface methodology combined with experimental design is applied to investigate the characteristics and optimize the magnetic suspension for vibration -free table.

Recently, Interior Permanent Magnet Synchronous Motor(IPMSM) is widely used in the industry applications such as power train for hybrid vehicles and compressor motors of air-conditioner due to its high power density and wide speed range. In designing motors, pole slot combination should be chosen properly according to the use of the motor and driving method in the initial design stage, accordingly there have been many researches about pole slot combination. As a part of the studies, this paper presents a comparison of characteristics of concentrated winding IPMSM, such as back-emf, Total Harmonic Distortion(THD) and core losses for each pole slot combination. By comparing the characteristics of each model, this paper can be a guide or reference in determining pole slot combination in the initial design stage.

Nowadays, the global interests are concentrated on the preserving of the clean environment, and the diminishing of the dependence on the fossil energy, and among the possible alternative energies, the wind turbine generating system is considered to be the best suited to produce high efficiency energy, without affecting the natural environment. The permanent magnet generators were been used for the wind power generating, for long time, with continuous efforts to improve the generating efficiency. And the latest trend on it is to develop an AFPM(Axial Flux Permanent Magnet)type, which is composed in the structure of rotor and stator shaped in the disc forms, and the direction of the flux at the air gap runs in parallel to the shaft. This thesis is on the study concerning with the analysis of the characteristics of the 5 kW at 300rpm direct drive AFPM generator which is suitable for the small scale wind turbine generating system. In it, the Electro-magnetically Coreless AFPM was been analyzed, the prototype generators been made, concentrated on interpreting the characteristics of the power output, and verifying it through the theoretical study and practical tests.

Based on the requirement of high power and efficiency in automobile systems, this paper describes an investigation for the optimum design of a permanent magnet reluctance motor(PRM), and then the characteristics of this kind of motor is compared with that of a interior permanent magnet(IPM) motor. The IPM of 4-pole with 6-slot is redesigned into a PRM, which has the same stator and different rotor structure with IPM. Through finite element analysis(FEA) and equivalent circuit method, the PRM has higher salient ratio, higher efficiency at high speed, and lower iron loss compared with IPM.

This paper deals with the optimum rotor design approach about the multi-layer design of the buried magnets in an Interior Permanent Magnet Synchronous Motor (IPMSM), on the efficiency improvement by using Response Surface Methodology (RSM). In the multi-layer design of the prototype 15kw IPMSM, the constant amount of buried PM is split from the single-layer into double-layer design for improving the efficiency characteristics. The optimum double-layer rotor structure is built with the help of RSM analysis. The improvement of IPMSM efficiency is verified by the Finite Element Method (FEM) results comparison with the prototype single-layer IPMSM.

This paper describes the effects of rotor-bar broken in induction machines. The analysis has been made on 7.5kW, 4P, 1,768[rpm], three-phase induction motors in a healthy and broken-rotor bars fault conditions at rated loading conditions. The effects of the rotor-bar broken, magnetic force are investigated by finite element method (FEM) and experiment. The results can be useful for real-time on-line monitoring of an induction motor.

This paper presents a drive strategy to reduce torque ripple of a permanent magnet Brushless DC Motor(BLDCM) with short $120^{\circ}$ flat top Back Electromotive Force(Back-EMF). In this strategy, the phase Back-EMF is divided into four sections. Then, in each section the phase current is regulated by corresponding PWM duty ratio to compensatethe torque ripple caused by imperfect Back-EMF. A program based on this strategy has been implemented in MATLAB@Simulink. The validity of the presented method is verified by simulation results.

In case of a difference exist between the experimental value and estimated value of back-emf, there can be a difference of turn number or residual flux density of permanent maget of the motor. In order to presume the turn number, the average length for each coil is used to calculate the resistance. However in producing the motor, doc to the tension of coil, the outer diameter of coil becomes smaller, and then the resistance estimated by average length for each coil is not correct. Therefore in this paper, through the comparison of experiment value and estimated value of inductance, a method of presuming the turn number and PM's residual flux density of an IPM motor is presented. The inductance of IPM motor changes with the rotor position, therefore the rotor part is taken out and then the inductance in open circuit condition is measured. In the analytical calculation, 3D FEM(Finite Element Method) is used, which can consider the leakage flux of end turns in frinzing effect.

Performance comparison of IPMSMs with distributed and concentrated winding is presented in this papcr. Two IPMSMs have been designed and fabricated with identical rotor dimension, air-gap length, series turn number, stator outer radius, and axial length except winding configuration. Basic parameters and machine performance, such as resistances, back emf, output torque, and efficiency, are compared. From the comparison results, motor design considering winding configuration is discussed.

This paper analyzes the principle and feature of the piezoelectric ceramic print head for the image printing of industrial inkjet plotter, and apply the Drop-on-Demand method that can adjust an ink drop size in accordance with the certain time adjustment. In order to do this study, drive frequency is selected at maximum 8.3[kHz] which can be operated within resonance frequency range of the piezoelectric ceramic. Drop controlling was realized according to pulse waveform the drive voltage, and grey-scale and satellite diminution method were applied for printing of high resolution image. A feasibility study of the result will be demonstrated by constructing the experiment equipment.

In motor design, an important factor is the content of silicon in coss material, which can effect the saturation of magnetic circuit and coss loss. While the content of silicon is high, the core loss will be reduced. At the same time, in order to assure the effective flux, the magnetizing current must be increased and then the copper loss becomes higher. Therefore the material with high content of silicon, which is used in the motor, can not always give the high efficiency. In this paper flux linkage of two different material s10 and s60 is compared according to the operating region and then exciting current to obtain same flux is estimated. By comparing core loss and copper loss between two material with the estimated current and flux linkage, this paper presents a criterion in determining the material for higher efficiency

본 논문은 Slotless BLDC 모터를 고출력화 하기 위해서 나선형(Helical)방식을 적용하여 모터의 고출력화를 이루는 방식에 대한 연구이다. 기존의 SlotlessBLDC모터는 코깅이 없고, Slot이 없으므로 소형화에 유리한 장점을 지녔다. 반면에 공극의 자속 밀도가 낮아 출력을 높이는데 한계가 있었다. 따라서 본 논문에서는 기존의 SLBLDCM의 단점을 극복할 수 있는 Helical 방식을 제안하였다. Helical 방식을 적용할 때 기존의 인덕턴스 영향으로 인한 전류 확립에 한계가 있었으나 본 방식을 적용 시 높은 전류를 흘릴 수 있었으며 이로 인해 고출력화를 이룰 수 있었다. 아울러 Helical 방식을 취하므로 높은 전류로 인한 발열문제까지도 동시에 해결할 수 있는 장점이 있었다. 본 논문에서는 Helical 방식을 적용하여 기존대비 출력을 15%이상 향상시킬 수 있었으며, 온도 상승도 10%이상 억제할 수 있었다.

본 논문은 청소기용 BLDC 전동기 모터에 기존의 전기강관이 아닌 SMC(Soft Magnetic Composite)를 적용하여 진공청소기용 BLDC 전동기 모터 설계를 하는데 있다. 본 논문에서 사용한 SMC는 순철 분말에 전기적 절연 코팅을 실시한 새로운 재질로 현재 많은 연구가 진행 되고 있는 분야이다. 그러나 재질의 특성에 적합한 모터 설계에 관한 연구는 미진 하였다. 따라서 본 연구는 진공청소기용으로 많이 사용되는 BLDC 모터에 SMC를 적용 하였을 때 BLDC 전동기의 특성을 알아 보고자 하였다. 본 연구에서 SMC재질을 사용 할 때는 어느 조건에서 사용함이 유리한지 알 수 있었다. 또한 고속 청소기에 적합한 설계를 실시한 결과 SMC 재질의 낮은 투자율로 말미암아 인덕턴스가 감소하고, 전류가 높아져, 출력 증대 되는 것으로 나타 났다. 향 후 본 연구는 SMC를 이용한 BLDC 모터 설계 시 설계 기준으로 이용 될 수 있을 것으로 사료된다.

To investigate a arc behavior when the flux density linking arc current is different, two kinds of models having the different flux density with each other are proposed. Calculations of the flux density and the electromagnetic force acting on arc column using finite element method is described in this paper. And, arc behavior photographs by the high speed camera are illustrated at breaking DC 100V, 100A on the resistance load. So, the arc driving forces are compared with according to the arc types.

외전형 모터는 내전형 모터에 비해 소형화 및 경량화 시킬 수 있는 특징을 가진다. 그러나 회전자와 고정자간의 공극사이에 이심률이 있을 때, 불균형 모멘트로 인한 토크 리플이 내전형보다 더 크게 일어나는 단점이 있다. 이전의 연구들은 회전자 슬롯 형상의 변화에 따른 모터의 변화를 유한요소해석법을 통해 알아보았다. 우리는 이러한 유한요소해석법을 통한 시뮬레이션을 통해 외전형 모터에서 이심률이 발생 및 증가함에 따라 나타나는 토크 리플을 줄일 수 있는 최적화된 슬롯형태를 찾아보았다.

본 논문은 기존의 전기강판 재질을 이용한 모터가 아닌 SMC 재질을 이용한 모터 성형 시 발생 될 수 있는 문제점이 모터의 자기적 특성에 미치는 영향에 대해 분석 하였다. 기존의 전기 강판 재질 모터에서 밀도는 전 영역에서 고른 분포를 갖는 반면에, SMC를 이용한 모터는 위치와 형상에 따라 다른 밀도와 응력 분포를 지닌다. 따라서 본 논문에서는 이러한 SMC 재질을 이용한 모터의 특성이 전기적 에너지 변환 과정에 미치는 영향에 대해서 분석 하기위해, 고속모터(30000rpm)급 모터에서 silicon steel 재질 모터와 SMC 재질모터를 비교 하였다. 비교결과 SMC 재질 모터의 경우 밀도 편차가 5.8%이상 발생되었으며 이는 전기적 특성에 10%이상 영향을 미치는 것으로 나타났다. 특히 고속모터의 경우 자속 포화가 심해 일정하게 높은 밑도 특성이 요구 되는 것으로 파악 되었으며, 향후 이 방법은 SMC 재질을 이용한 모터 설계에 유용하게 이용 될 수 있을 것으로 판단된다.

우리는 이전 논문을 통해 Air blower용 모터에서 널리 사용되고 있는 단상 유도기를 기존의 분포 권선 방식에서 벗어나 집중 권선 방식을 사용하여 설계한 결과 생산 공정의 단계를 줄이고 많은 생산 비용을 줄일 수 있었다. 또한 집중 권선형에서 발생할 수 있는 고조파 문제를 로터의 skew와 overlap 권선 방식을 이용하여 해결 할 수 있음을 증명하였다. 그러나 이러한 이점에도 불구하고 시제품의 특성을 측정한 결과 집중 권선형 모터의 자계 불균형 때문에 기존 분포권 모터에 비해 소음과 진동 특성이 좋지 않은 결과를 보였다. 이에 본 논문에서는 소음과 진동 특성을 고려하여 기존의 기동 및 정격 토크 특성을 유지하면서 토크 리플을 저감할 수 있는 방법을 로터의 Skew 각도 영향, 권선 사양 및 스테이터 및 로터 형상 등을 고려하여 새롭게 설계하였고 그 결과를 제시하였다.

Single phase switched reluctance motor has a merit in practical use because it has simple operating drives and control systems, very high energy density per unit volume comparing with three phase SRM. But it must have a starting device. This paper presents a single phase SRM model with a stepped rotor pole, so as to reduce the torque ripple. Also it is simulated the designed prototype model by FEM for the prediction of characteristics.

This paper covers start-up characteristic of three phase induction motor. When three phase induction motor is started, the inrush current occurs. There are several ways of reducing starting current of a three phase motor. In this paper will explain and propose the types of part windings in order to reduce the starting current.

Reduction of AC losses is very important for realizing HTS cable and it had been reported that the same layer current controlled by twisting pitch and direction could reduce the AC losses effectively. During the long-term development of HTS cables, the superconductor AC losses will need to be reduced to a level determined by the economics of each installation and the efficiency of the refrigeration. Theoretical models have been developed to predict the magnitude of the losses in cables composed of several layers of flat HTS tapes. This paper is manufactured mini-model HTS cable and voltage signal line to spiral shape. Mini-model HTS cable is composed of 13 HTS tape. We measured to critical current and AC loss and compared used lock-in-amp to cancel coil. This data is useful to HTS cable of DAPAS program.

본 논문은 부하상태에 따른 매입형 영구자석 전동기에서의 역기전력 파형을 제시하였다. 유한요소해석에 기초한 고정투자율법을 사용하여 무부하 상태뿐만 아니라 부하상태에 따른 역기전력 파형을 해석하였고, 매입형 영구자석 전동기의 설계변수가 역기전력 파형의 고조파 성분에 미치는 영향을 조사하였다.

The squirrel case induction motor has widely used in the driving of the blowers but it is low efficiency and hard to control. So, the damper is used for the control of a flow and it cause to low the driving efficiency. Our laboratory has proposed the single-phase SRM(switched reluctance motor) for driving blowers. It has salient pole structure and can be reduced a number of semiconductors than three-phase SRM. But it can not be starting by itself and has heavier torque ripple than three-phase SRM. For self-starting the single-phase SRM is required the starting device which place the rotor at the rising inductance slope. On this paper, the electromagnet starting device is designed to generate the starting torque and to fix the rotating direction of the single-phase SRM which is fabricaed to use a blower.

This paper proposes a novel design method for flux barrier which built in q-axis in rotor of IPM type BLDC motor. It aims to reduce the motor vibration with reduced cogging torque and lessened torque ripple by the sinusoidal waveform distribution of flux generated in the permanent magnet, which results from designed flux barriers. Design of flux barrier optimized using the Taguchi methods that considered multiple quality characteristics, such as cogging torque, average torque and efficiency are considered. The result of proposed method is compared and verified with 2D finite element method (FEM).

A 2.0T class HTS conduction cooled magnet was designed. Designing of magnet shape was performed through two steps. First step is to find a basic cross section for minimize the amount of conductor used and second step to optimize the coil shape to satisfy the magnetic field homogeneity. The magnetic fields was analyzed with FEM and the critical current value of magnet was also expected with the result of field analysis and the Ic to B curve of Bi-2223 HTS tape.

This paper presents the 3D finite element analysis of contactless power supply with linear servo motor. The voltage source is used to analyze the characteristics of contactless power supply. The primary, secondary self and leakage inductances and the capacitances of a resonant circuit are calculated by the previous finite element analysis are used. Also the driving circuit to supply the power to the linear servo motor is designed. The characteristics analysis of contactless power supply considering the linear servo motor is done.

In the case of the interior permanent magnet synchronous motor (IPMSM), it is important to know the accurate machine parameters in the design step. In particular, d- and q- axis inductance are expected to have ripple characteristics, due to the mechanical structure and the degree of magnetic saturation. In this paper, this feature is expressed as inductance variation. Inductance variation of the IPMSM is calculated with finite element analysis, and the reason for inductance variation is identified. Finally the validity of this paper is verified by the comparison with the experimental results.

This paper proposes a novel structured 3-DOF(Degree-of-Freedom) spherical motor. 3-DOF spherical motor presents some attractive features by combining pitch, roll, yaw motion in a single joint. The proposed motor has pole which is electromagnetic in stator and rotor. poles produce magnetic flux through by exciting current then produce torque. We show a novel structured rotor to avoid mechanical overlapping of each coil in rotor. The validity of the analysis is confirmed by 3D finite element method.

This paper describes the effects of air gap eccentricity in induction machines. Asymmetric electro-magnetic force caused by the frictional worn bearing, rotor misalignment and unbalanced rotor etc. generates an asymmetrical operation, vibration and electro-magnetic noise. In this paper, we focus on investigating the asymmetrical operation considering of unbalanced magnetic force in squirrel-cage induction motor with 380 [V], 7.5 [kW], 4P, 1,768 [rpm]. The effects of the rotor eccentricity, magnetic force are investigated by finite element method (FEM) and experiment. The results can be useful for on-line monitoring of an induction motor.

This paper proposes a new method for detecting broken rotor bars in a squirrel-cage induction motor. The air-gap flux variation analysis was done using search coils inserted in stator slots when broken rotor bar occurs. An accurate modeling and analysis of air-gap flux variation in the induction motor are developed using finite-element(FE) software packages, and measurement of the flux are made using search coils. The simulation was done for the induction motor with 380 [V]. 7.5 [kW], 4 Poles, 1,760 [rpm] ratings using the commercial FE analysis tool. The simulation and experiment results can be useful for detecting the broken rotor bar of an induction motor.

The line-start permanent magnet synchronous motor has a high efficiency and an advantage in constant speed operation regardless of the effect of load variation. However it is difficult to predict the performance of characteristics accurately, because of the unbalanced starting torque with the initial starting position of the rotor and the generation of a break torque. In this paper the dynamic characteristics of the line-start permanent magnet synchronous motor are described and compared with those of the squirrel-cage induction motor through the simulation to find the characteristics of the permanent magnets and the rotor bars in the line-start permanent magnet synchronous motor.

본 논문에서는 Brushless DC Motors(이하 BLDC Motor이라 함)의 영구 자석의 오버행에 따른 진동, 소음 특성에 대하여 다루었다. 비대칭 오버행 구조에서는 Z축 방향 힘이 발생한다. 이는 베어링에 손상을 입힐 뿐 아니라 큰 노이즈와 진동을 유발시킨다. 따라서 진동과 소음의 감소를 위한 자석 오버행 효과 해석이 필수적이다. 본 논문에서는 비대칭 영구 자석 오버행 효과를 해석하고 BLDC Motor에서 발생하는 소음과 진동을 분석하였고 비대칭 영구 자석 오버행 효과를 고려하여 Z축 방향의 영향력을 계산하기 위하여 3차원 유한요소법(3D FEM)을 사용하였다.

디텐트력은 철심형 영구 자석 전기기기의 구조상 피할 수 없는 기기 특성이며 원통형 선형발전기에서도 기기의 정상적인 동작을 방해하는 요인으로 작용한다. 특히 정격 외부 입력이 작은 경우 디텐트력은 기기의 성능에 크게 영향을 미칠 수 있으며 이를 저감할 수 있는 설계가 필수적이다. 본 논문에서는 여러 가지의 디텐트력 저감법 중 이동자의 극 피치 조정을 통해 디텐트력을 저감하고자 하였다. 극피치의 변화는 디텐트력 외에도 역기전력 파형에 영향을 주게 되므로, 기기의 목표 성능을 만족하기 위해서는 디텐트력과 역기전력을 함께 고려하여야 한다. 제안된 설계안은 유한요소법을 이용하여 해석되었으며 이를 통해 얻어진 결과를 고려하여 최종 모델을 도출하였다.

최근의 선박 추진시스템은 기존의 엔진, 터빈 등의 구동 원에서 선박의 발전기로부터 선체 외부의 프로펠러와 일체형으로 구성된 모터를 구동하여 추진하는 전기추진식으로 변화되고 있다. 특히, 히토류계 영구자석재질의 발달로 인하여 대형 선박의 추진을 위한 대용량 자석계자형 BLDC와 영구자석형 동기전동기의 설계가 가능해 졌으며, 이에 대한 연구구도 활발히 이루어지고 있다. 그러나 이도 중 소형 선박기기에 한정되어 있으며, MW급 이상의 대형기기의 설계 연구도 일부 선진국에서만 진행 되고 있는 실정이다. 이에 본 연구에서는 5MW, 150rpm급 대용량 추진전동기 설계에 관한 연구를 하였다. 본 설계 모델은 오랜 기간 해양 운행을 해야 하는 선박특성 상 중요한 부분인 에너지 효율을 높이기 위하여 인버터를 전동기 내부에 배치한 구조로 부피와 중량을 줄이고, 더불어 속도에 따라 인버터를 커플링하여 상변환이 가능한 전동기를 설계하였다.

In this paper, a novel permanent magnet array is proposed and the magnetic field distribution is evaluated analytically by using magnetic scalar potential. The characteristics of the synchronous permanent magnet planar motor with this novel magnet array such as inductance, back-EMF, and force are calculated by analytical method. The superiority and feasibility of the novel magnet array are verified by comparing with Asakawa array, Chitayat array, and experiment data. Otherwise, the force is developed form 27.77[N] to 30.37[N] by using the method of genetic algorithm.

This paper deals with skew and overhang effects of Permanent Magnet of PMLSM. The detent force and thrust characteristics considering skew and overhang effects of permanent magnet are analyzed by 3D FEM and the results are compared to experimental values

In this paper, a synchronous permanent magnet planar motor (SPMPM) with Halbach array is proposed for its performance improvement. The magnetization and flux density distribution are obtained by magnet scalar potential; the characteristics such as back-EMF and thrust are evaluated. It can be concluded that the analysis of SPMPM with Halbach magnet array is credible and feasible.

자기 기록 시스템이 더 높은 기록 밀도를 가지려면 기록 미디어에 더 작은 공간을 가지는 비트를 기록할 수 있어야 한다. 이를 가능하게 하기 위해서는 더 작은 비트를 보존 할 수 있는 고 보자력 기록 미디어와 이를 기록할 수 있는 자기 기록 헤드가 있어야 한다. 자기 기록 시스템에서 기록 밀도와 함께 중요시 되는 것이 바로 기록 속도이다. 시스템이 발전 할 수록 요구되는 속도 또한 높아지고 있다. 기록 속도가 빨라지려면 기록 주파수가 높아지고 기록 미디어의 회전 속도가 빨라져야 한다. 자기 기록 헤드는 자화되어 있는 고 보자력 기록 미디어 위를 빠른 속도로 직선 운동하고 있는 형태가 되고 이로 인하여 자기 기록 헤드에 와전류가 발생하게 된다. 발생되는 와전류의 형태는 기록 미디어에 자화된 형태에 따라 달라질 것이고 또한 자기 기록 미디어의 회전 속도와 와전류가 발생되는 기록 헤드의 전기전도도에 따라 변화 된다. 본 연구는 이렇게 발생된 와전류를 3차원 유한요소법을 이용하여 분석한 수 이 와전류가 기록 필드에 미치는 영향을 분석하여 제시 하였다.

Reduce AC loss is very important in superconductor power machine. And HTS power application are needed an increment of current capacity. in this paper estimate AC loss effect and increase of current according tocomposition stack with 1G wire and 2G wire by measurement. A Method of composition stack are YBCO-BSCCO, YBCO-BSCCO-BSCCO-YBCO and BSCCO-YBCO-YBCO-BSCCO. also, test result compared analytic equation by Norries

최근 안전인증 기술기준의 국제규격(IEC) 부합화에 따라 소형 퓨즈의 DC 시간/전류 특성(DC Time/Current characteristic, 이하 DC 용단특성)에 대한 시험이 중요한 성능평가항목으로 부각되고 있다. 특히 DC 용단특성을 시험하기 위해서는 규격에 적합한 DC 발생기 및 DC 용단시간도 정확하게 측정할 수 있는 시스템이 구축되어야 하므로, 그 성능 평가설비 또한 매우 중요하다고 할 수 있다. 본 논문에서는 안전기준 및 IEC 국제규격을 분석하고, 분석된 규격을 토대로 성능평가설비를 설계하여 국제적 수준의 시험기관 위상에 걸맞은 성능평가기술 기반을 구축하였다. 구축된 설비 및 개발된 성능평가기술은 향후 시험평가기술의 국제화에 중요한 역할을 할 것으로 기대된다.

최근 자동차 브레이크의 전기적 시스템에 대한 연구가 활발히 진행되고 있다. 이와 관련하여 본 논문에서는 자기 엑추에이터 브레이크 시스템(MABS)을 분석하였다. 주행 도중 차량의 이상 및 긴급 상황 발생시 MABS는 전기적 메커니즘을 통해 차량을 제동할 수 있다. MABS는 회전하고 있는 휠에 초당 수십회 작용하여 점차적이고 효율적으로 휠을 제동한다. 이는 제동시간의 단축과 안정성에 있어 향상된 성능을 보인다. 본 연구에서는 유한요소법을 적용한 시뮬레이션을 통해 MABS의 동작 특성을 분석하고, 실제 자동차의 상황을 가정하여 제동하는데 소요되는 시간 및 작동 회수 등에 대해 분석하였다.

This paper presents methods to reduce acoustic noise in interior permanent magnet (IPM) motor. Mechanical and magnetic sources are considered to reduce noise of the machine, and structural and electromagnetic designs are performed. In the structural design to reduce mechanical source, the structural resonances are moved to higher frequency for enhancement of stiffness. Then, the electromagnetic design to reduce magnetic source, the amplitudes of magnetic force harmonics are reduced by using objective function of response surface methodology (RSM). The validity of the design process and objective functions is confirmed with their calculated and experimental results.

Interior permanent magnet synchronous motor(IPMSM) has higher power density than other PM(permanent Magnet) machines due to reluctance torque in addition to magnetic torque, and the ratio of magnetic and reluctance torque has influences on motor characteristics such as input current, efficiency, power factor, etc. Therefore, this paper presents the output characteristics of IPMSM according to the ratio magnetic and reluctance torque of IPMSM and discuss the design strategy of IPMSM.

Inductance can be defined as several kinds of slops on the B-H curve, and at is classified into apparent, effective, incremental inductances, etc. In many research cases, its calculation and measurement are partially dealt. However it is hard to find the clear explanation of the inductance in the voltage equation of PM machines, and even its relationship with those classified inductances in the view point of design and characteristics analysis. Moreover some previous definition of inductance can not be used for the inductance of coils in PM machines. Therefore, in this paper the inductance is redefined for voltage equation of PM machines, and the methods of calculation by using finite element analysis method and measurement are explained.

It is important to diminish noise source of an electric motor used in appliances. We studied on the noise reduction of BLDC motor to drive a fan. Especially, this study was focused on detent torque caused by interaction between a permanent magnet of rotor and groove in stator. This source and rotating system brought about a resonance. This paper showed that the higher harmonic component of this torque had a main factor to lessen noise. So, we had designed new magnets with shape like a peanut and pseudo-sinusoidal flux density for low-noise BLDC motor in refrigerator.

냉장고에 적용된 BLDC Fan Motor에 있어서 공진소음의 원인에 대하여 연구하였다. 연구에 있어서 종래의 가진 방법을 적용하기 곤란한 구조를 가진 소형 Fan & Rotor System의 동 특성 실험에서 전자 가진법 및 Microphone을 이용한 고유진동수 계측방법을 사용하고 그 타당성을 보였으며 연구결과, Pan과 Rotor System의 비틀림 고유진동수와 Fan의 굽힘 고유진동수가 BLDC Motor의 Commutating Torque Ripple에 의한 가진 주파수와 일치하여 공진이 발생하는 것으로 분석 되었으며 이와 관련된 주요 인자를 분석하고 대안을 제시하였다.

Bearingless Switched Reluctance Motor(SRM) have combined characteristics of SRM and magnetic bearing. Production of radial force for rotor shaft magnetic suspension is explained with differential stator windings. Bearingless SRM is simple structurally because the permanent magnet does not exist and bearing does not take the influence at the environment because it does not exist and has strong torque, and loss of bearing by bearing current has the advantage not to exist. In this paper, a design method of bearingless SRM for suspension power and starting torque is proposed. The design model is implement by maxwell.

리니어 모터는 일반적으로 회전하는 모터와 같이 여러 형상의 극간에서 발생되는 힘의 균형에 의해서 구동되는 것이 일반적이다. 특히 하나의 극간에서 미소 구동하는 리니어 모터는 구동력과 실제 이동하는 위치 사이에서 댐핑이나 무게와 함 사이에서 발생하는 가속력의 차이에 의해서 주어진 힘의 파형과 움직이는 위치의 괴적이 만들어가는 이동자의 위치 사이에는 다소 시간 처짐이 발생하게 된다. 본 논문에서는 구동력과 실제 이동하는 위치 사이의 시간 처짐의 원인으로 알려져 있는 딤핑의 조건을 변화시키고 이에 다른 구동력의 변화를 알아보았다. 댐핑이 전형 없는 조건과 댐핑이 조금씩 증가함으로 인해서 주어진 시스템의 기계적 공진 영역에서 발생하는 여러 가지 구동특성을 정량적으로 평가해 보았다. 60[Hz]가 공진인 이동자와 탄성체로 이루어진 시스템에서 58-62[Hz]에서 구동될 경우 힘의 주파수와 가해진 힘에 다라 이동자의 초기 거동을 알아보았으며 초기 0.3초 구간에서 구동되는 특성을 알아보았다. 전체적으로 이동자의 구동 괴적과 주어진 힘의 파형 사이에서 발생하는 시간 처짐은 댐핑계수에 가장 지배적인 영향을 받았으며 구동 힘의 주파수가 공진주파수보다 작으면 점점 증가하고 크면 점점 감소하는 경향을 가지며 공진주파수의 구동력이 가해진다면 시간 처짐은 거의 변화가 없음을 알 수 있었다.

일반적으로 초전도선재를 이용한 코일의 전자기력에 의한 스트레스 계산에 있어서는 코일의 전류밀도분포와 자속밀도분포의 선형적인 관계를 이용하나 아직까지 초전도체 특유의 비선형적인 특성을 이용한 스트레스의 계산은 미비하다. 본 논문에서는 13턴의 소형 싱글팬케이크 코일을 초전도의 특성을 적용해 해석하고 인가전류가 $0.3I_c,\;0.5I_c,\;0.8I_c$ 인 경우에 대해서 전자기력에 의한 코일의 스트레스를 유한요소법으로 계산하였다. 계산 결과 코일의 radial stress와 hoop stress는 모두 코일의 자속밀도분포와 유사한 모습을 나타내었다.

본 논문은 600 kJ SMES 모델 코일의 설계와 전자기력에 의한 모델코일의 스트레스의 해석에 관한 연구 결과를 나타낸다. 모델 코일의 설계에 적용된 초전도 선재는 77 K, 자기자계 하에서 115 A인 강화 선재이며, 모델 코일은 두 개의 팬케이크 코일로 구성한 모듈 코일 3개를 적층한 형태로 총 6개 더블 팬케이크 코일로 구성되어있다. 모델 코일의 임계전류는 전류를 인가하였을 때 코일에서의 최대 수직방향 자장을 이용해 Load Line을 나타내고, 이를 운전온도인 20 K에서의 $B-I_c$ 곡선에 적용하여 결정하였으며 236 A이다. 운전전류는 임계전류의 80%인 165 A로 결정하였으며, 이는 n-Value 손실을 고려한 값이다. 또한 해석적 방법을 이용해 코일에 전류를 인가하였을 때 전자기력에 의한 모델 코일의 radial stress와 hoop stress를 계산하여 나타내었다.

이미, 동기 발전기는 크게는 발전소에서 작게는 소형 자가 발전에 이르기까지 널리 사용되고 있다. 그러나, 수요는 급격히 증가하고 있으나 이에 대응할 수 있는 기술은 적절히 대응하지 못하고 있는 듯하다. 즉, 수요가 증가함에 따라 발전 시스템의 고효율화, 소형화는 당연한 요구사항이나, 현재 동기 발전기는 기존의 별 다른 진전이 없이 고전적인 방법에 의해 생산되고 있다. 그래서 정밀한 해석 기술에 바탕을 두어 내삽형 자석 동기 발전기의 설계치가 도출될 것으로 기대된다.

Superconducting fault currents(SFCLs) are expected to improve not only reliability but also stability of power systems. The analysis on current limiting operations of the flux-lock type SFCL, which consists of a flux-lock reactor wound an iron core and a YBCO thin film, was compared the open-loop with the closed-loop iron core of the subtractive polarity winding. In the SFCL, operation characteristics could be controlled by adjusting the inductances and the winding directions of the coils, then magnetic field induced in the iron core. The current limiting characteristics under the same experimental conditions were generated regardless of the iron core conditions. We confirmed that capacity of the SFCL was increased effectively by the closed-loop iron core. However, the power burden of the system could be lowered by the open-loop iron core.

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, inertia conversion the electric motor coach has slip phenomena. This paper proposes a anti-slip control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the anti-slip control is performed to obtain the maximum transfer of the tractive effort.

횡자속의 기본원리는 릴럭턴스 전동기와 같다. 발생한 힘밀도는 공극과 극간격에 반비례하고 기자력의 자성에 비례한다. 이러한 횡자속 선형전동기를 적용할 경우 추력의 변화로 인해서 진동과 힘의 불평형이 발생하는 것이 일반적이다. 본 논문에서는 이러한 추력 불평형과 진동특성을 향상시킬 수 있는 방법이 다상형으로 구동하는 방법이 있으며 힘을 균일하게 할 수 있고 전동기의 체적을 줄이고 진동특성을 저감시킬 수 있다는 것이라고 판단된다.

선형전동기(linear motor)는 일반 회전형 모터에 비해 직선 구동력을 직접 발생시키는 특유의 장점이 있으므로 직선 구동력이 필요한 시스템에서 회전형에 비해 절대적으로 우세하다. 선형전동기의 성능인 추력을 스테이터, 코어, 영구자석 등의 구성요소의 형상과 치수, 코어와 영구자석의 극간격, 공극, 코일의 권수에 따라서 결정된다. 본 논문에서 제안한 2kW급 단상 구동형 횡자속 선형전동기는 압축기 제작에 필요한 직경 50mm, 구동 스트로크 18mm로 설계하였다. 또한 pole pitch가 20mm로 설계하였으며 요구되는 평균추력은 940N이다. 제작된 압축기의 특징은 고정자와 이동자가 맞닿는 flux path를 넓히기 위해서 최대한 경사진 각도의 형상으로 제작하였으며 경사의 각도가 커지면 커질수록 압축기로 구동하는 이동자와 고정된 부위사이에서 발생하는 흡인력이 상쇄되는 구조이기 때문에 진동의 원인으로 가장 크게 작용한다는 디텐트력이 작다는 것이 특징이며, 진동특성 등에 유리한 것으로 판단된다.

본 논문에서는 디스크 권선과 레이어 권선의 장점을 가지는 연속디스크 권선의 변압기 적용가능성을 확인하기 위하여 전위된 병렬선재를 이용하여 연속 디스크 권선을 제작하였다. 제작된 연속 디스크 권선의 임계전류 및 교류손실 측정을 통하여 실제 변압기 권선방법으로의 적용 가능성을 확인 하였다. 또한 33 MVA 초전도 변압기의 고압측에 사용될 권선형태를 레이어 권선, 연속 디스크 권선을 적용하였을 경우 발생하는 손실을 계산하였다.

We have proposed a 100 MVA, 3 phases, 154 kV class HTS transformer which will substitute for 60 MVA conventional transformer. In this paper, we designed conceptually the structure of the superconducting windings of a single phase 33 MVA transformer. The power transformer of 154 kV class has a tertiary winding besides primary and secondary windings. So the HTS transformer should have the 3rd superconducting winding, it makes the cost of the HTS transformer high and the efficiency low. Further more we considered On Load Tap Changer (OLTC) in HTS power transformer. OLTC equipment is required for fitting to a power transformer by which the voltage ratio between the windings can be varied while the transformer is on load. We analyzed the electrical characteristics of the HTS transformer such as magnetic stress and AC loss.

Switched Reluctance Motor(SRM) is rotated by reluctance force generated between rotor pole and stator pole. So SRM must be switched by exciting current according to rotor position. but SRM takes the advantages of high speed driving and very simple structure. The single phase SRM can not be start by itself and torque ripple is generated more than multi-phase SRM. But mechanical structure and driver is simpler than multi-phase SRM. The single phase SRM driver is composed with the absolute encoder and DSP to control exciting section and current, and is supplied by constant voltage. So The paper is intend to measure the speed charactrer of double silent pole type SRM by using the unipolar driving curcuit.

The main purpose of this paper is to describe a novel ultrasonic motor which is suitable for small information devices. With a bending mode of a bimorph structure having relatively large displacement, the input voltage and frequency could be reduced. The overall shape of the motor is very simple, so it could be manufactured and miniaturized with ease. From the simulated results, such as mode and harmonic analysis, resonance mode, operating frequency, and displacement are determined. The experimental results are compared with the simulated one finally.

An obstacle is an element for power to small and slim the existing portable communication set. Developed Inductor for Chip-type electric power in needs to solve this. Stack applied Process, and used gap of a magnetic path, and made a height of an element to 1.0T or below, and this development commodity did product for saturation prevention to materials of silver. Saturation current characteristic of Chip-type inductor was low compare with winding-type inductors, but bulk against performance were had superior excellence. Chip-type inductor can raise performance per unit volume compared with the existing inductors at these papers. Therefore, acceleration can get growth of small and slim of a mobile product done, and expect.

This paper presents a design and analysis solutions for the general class and control parameter estimation of slotted iron-cored Permanent Magnet Linear Synchronous Motor with Halbach magnetization stator and 3-phase winding mover. In our design and analysis, stator consisting of permanent magnets and slotted iron-cored coil mover are treated in a uniform way via magnetic vector potential. For one such motor structure, we give analytical formulas for its magnetic field, back electromotive force and trust force. Moreover, the detent force are calculated by the relative permeance function. In good agreement with the estimated values from the analyses, the experimental results and Finite Element Method (FEM) confirm the validity of the design and analysis framework.

This paper presents an analytical solution to calculate parameters of permanent magnet synchronous motor equipped with surface-mounted magnet by using transfer relations theorem(TRT) in terms of two-dimensional model in polar coordinates. The analytical results are validated by comparison with finite element analyses (FEA).

This paper presents test results for the speed control system of PMSM (Permanent Magnet Sychronous Motor). The PMSM has higher efficiency and torque per volume than other motors because PMSM use permanent magnet of high energy density instead of field winding. In this paper, current and speed control of PMSM using DSP was accomplished.

Using the MATLAB/SIMULINK, this paper presents dynamic simulation model for 6MW wind power generation systems with the DFIG considering distribution systems and performs the dynamic analysis of wind power systems.

In high-speed PM machines, rotor losses form a larger proportion of the total losses than usual in conventional low speed machines. In order to maintain the mechanical integrity of a high-speed PM rotor intended for high-speed operation, the rotor assembly is often retained within a sleeve or can. The sleeve is exposed to field produced by the stator from either the slotting or the mmf harmonics that are not synchronous with the rotor. These non-synchronous fields cause the significant rotor losses. An optimum design of high-speed PM machines requires the accurate prediction for these rotor losses. On the basis of analytical field analysis and 2D finite element analysis (FEA), this paper deals with the rotor losses.

This paper deals with analysis of linear switched reluctance motor at high speed. First, we defined turn-on position at inductance profile. Second, in turn-on section, we analyzed characteristic of linear switched reluctance motor according to speed. Also, we used finite element method at analysis process.

This paper deals with the dynamic simulations and experiments of moving-coil linear actuator with/without spring. Dynamic simulation algorithm is established from the voltage and motion equation. Finally, for various values of frequency, dynamic simulation results for characteristics of current and displacement of moving-coil linear actuator with and without spring are presented and confirmed through the experiments.

The energy storage systems are being widely researched for the electric power. The operations running in a vacuum chamber mainly consists of a composite flywheel rotor, superconductor bearings, a motor/generator and its controller. Among composed the apparatus, the floating magnet bearing consists of the ring-type permanent magnets with epoxy resin impregnation for reinforcement and surface protection. In order to storage as much energy as possible, the flywheel is supposed to be rotated with very high speed. The magnetic field is analyzed by using the Maxwell 2D/3D for the simulations.

본 논문에서는 액체의 가열을 위한 유도가열기에서 와전류가 발생하는 중심코어의 형태에 따른 유도가열기의 성능을 비교하였다. 특히 코어가 여러 층의 도체로 이루어졌을 경우의 시스템 성능의 변화에 대한 해석과 실험을 수행하였다. 유도가열의 수치적인 해석은 상용 프로그램인 Maxwell을 사용하였으며, 실험을 통하여 유한요소해석 모델을 검증하였다. 본 연구를 통하여 가열되는 코어가 여러 층으로 이루어져 있을 경우 유도가열기의 성능이 향상됨을 알 수 있었다.

In industrial field, electric fork-lift has been mainly powered by batteries which are varied from DC 36V to 80V. Operating electric fork-lift truck depends on stable electric power supplies which are ensured by using Switched Mode Power Supply (SMPS). This paper presents design of SMPS for stable electric power supply. The SMPS has much strength such as high effectiveness, low cost and high stability of output voltage. At the same time, SMPS is small and multi output and has simple design of circuit.

This paper proposed the extraction method of reactor parameters in atmosphere plasma power supply. This methods is performed by detection of phase difference between inverter voltage and current, and extraction of impedance through active, reactive power. The validity of the proposed scheme is investigated through simulation results.

In this paper, a novel new pulse power generatorbased on IGBT stacks is proposed for pulse power application. Proposed scheme consists of series connected 9power stages to generate maximum 60kV output pulse and one series resonant power inverter to charge DC capacitor voltage. Each power stages are configured as 8 series connected power cells and each power cell generates up to 850VDC pulse. Finally pulse output voltage is applied using total 72 series connected IGBTs. The synchronization of gating signal is importantfor series operation of IGBTs. For gating signal synchronization, full bridge inverter and pulse transformer generates on-off signals of IGBT gating and specially designed gate power circuit was used.

Comparing with the conventional transformer without the air gap, a contact-less transformer with the large air-gap (4.8cm) between the long primary winding and the secondary winding has the increased leakage inductance and the reduced magnetizing inductance. By the increased leakage inductance and the reduced magnetizing inductance on the primary of the contact-less transformer, a good deal of the primary current circulates through magnetizing inductance, which results in a massive loss in contact-less power supply (CPS). In this paper, the efficiency characteristics of the contact-less power supply using a series resonant converter is analyzed and simulated. The results are verified on the simulation based on the theoretical analysis and the 1.8kW experimental prototype.

For the interior permanent magnet synchronous motor(IPMSM) drive to operate above the base speed in the constant horsepower region, field weakening control is applied. However, the field weakening control was not almost applied to sensorless control of the interior permanent magnet synchronous motor. In this parer, field weakening control is applied to the sensorless control of IPMSM based on an instantaneos reactive power. The effectiveness of the Proposed system is verified by the experimental results.

This paper presents a sensorless speed control of an interior permanent magnet synchronous motor using an adaptive integral binary observer and fuzzy logic controller. In view of composition with a main loop regulator and an auxiliary loop regulator, the binary observer has a property of the chattering alleviation in the constant boundary layer. However, the steady state estimation accuracy and robustness are dependent upon the width of the constant boundary. In order to improve the steady state performance of the binary observer, the binary observer is formed by adding extra integral dynamics to the switching hyperplane equation. Also, because the conventional fixed gain PI controller are very sensitive to step change of command speed, parameter variations and load disturbance, the fuzzy logic controller is used to compensate a fixed gain PI controller. Therefore, a gain PI is fixed and the IPMSM is drived at another speed region. The effectiveness of the proposed the adaptive integral observer and the fuzzy logic controller are confirmed by experimental results.

본 논문에서는 전동기의 속도제어에 필요한 관성과 마찰계수를 추정하는 알고리즘을 제안한다. 속도관측기에서 발생하는 추정속도와 실제속도로부터 최소자승법을 이용하여 관성과 마찰계수를 동시에 추정한다. 모의실험을 수행하여 추정관성과 추정마찰계수가 제안된 방법에 의하여 각각 실제값에 수렴함을 보인다.

This paper presents a direct instantaneous torque control (DITC) of Switched Reluctance Moto (SRM) with a novel 4-level converter to obtain smooth torque and dynamic performance improvement. The DITC method can reduce the high inherent torque ripple of SRM drive system, but driving efficiency and dynamic performance are somewhat low due to the slow excitation current build-up. Since the 4-level converter can obtain a addition high voltage to get fast excitation current and demagnetization current, so, it can improve dynamic performance easily. As a high performance SRM drive system with low torque ripple and high dynamic performance can be implemented. The validity of proposed method is verified by some computer simulations and comparative experiments.

This paper proposes a control algorithm for 3-phase 4-wire series active power filter. This control algorithm compensates harmonics and neutral line currents which are generated by balanced or unbalanced nonlinear loads. The advantage of this control algorithm is direct extraction of compensation voltage references. Therefore, calculation time is shorten and the performance of series active power filter is improved. Compensation principle of the proposed control algorithm is presented in detail. Experimental results are shown to verify the effectiveness of the proposed control algorithm.

본 논문에서는 새로운 양방향 ZVS PWM Sepic/Zeta 컨버터를 제안한다. 제안한 컨버터는 PWM 제어가능한 컨버터로서 입력과 출력전압의 극성이 같은 비반전 컨버터의 특징을 지니며 DC 전압의 전달함수가 양방향 모두 M=D/(1-D)로 동일하다. 또한 각방향으로 전력전달시 다이오드와 병렬로 연결된 MOSFET가 다이오드의 'ON'시 동시에 'ON'되어 Sychronous Rectifier로 동작하므로 도통손을 저감하였으며, Auxiliary Resonant Commutated Pole를 사용하여 저감된 스위칭 손실을 갖는 특성을 지니고 있다. 또한 Transformer 버전이 존재하므로 입력과 출력사잉에 전기적 절연을 필요로 하는 실제응용에 유용하게 사용할 수 있다.

This paper deals with a 3-phase voltage disturbance generator. The proposed generator can be used for the performance teat of custom power devices with nonlinear load characteristics as well as linear load. The principle of the voltage sag, swell, outage, and unbalance generation is described. The switching pattern for the SCR thyristors in each mode is analysed to guarantee the system reliability. The validity of the proposed scheme is verified through simulation result.

본 연구는 광 출력이 조정이 가능한 UV Lamp용 안정기에 관한 연구이다. UV Lamp는 하수 종말 처리장의 하수 처리에 사용되고 있는데, 기존의 UV Lamp용 안정기는 처리되는 하수의 양과 관계없이 일정한 출력을 내는 방식으로 항상 일정의 전력을 소모하였다. 본 연구에서는 하수의 양에 따라 광 출력을 최대 출력의 50%까지 안정기에서 조정하는 방식으로 하수의 양이 적을 시에는 광 출력을 줄여 전력의 소모를 줄일 수 있고, 아울러 고가의 UV Lamp의 수명을 연장할 수 있어 UV Lamp 및 교체 비용의 감소를 기대할 수 있다.

An integrated inductor using the low-temperature co-fired ceramics(LTCC ) technology for low-power electronics was fabricated. In the inductor NiZn ferrite sheet(${\mu}_r=230$), was embedded to increase inductance. The inductor has Ag spiral coil with 14 turns($7turns{\times}2layers$), a dimension of 0.6mm in width, 10um in thickness, and 0.15mm pitch. To evaluate the inductance, including the parasitic resistance, the fabricated inductor was calculated and measured. It was confirmed that calculated values were very close to the measured values. Finally as an application of the LTCC integrated inductor to low power electronic circuits, a LTCC buck DC/DC converter with 1W output power and up to 0.5MHz switching frequency using the inductor fabricated was develop.

The Analysis on AVR-MVR conversion trouble for Excitation System AVR-MVR conversion is a very important function to transfer AVR to MVR when the grid has abrupt changes or the control system has some problems. Therefore through studying on AVR-MVR transfer scheme, and problems which might happen when transferring, we would like to enhance the stability of generator and control system.

This paper discusses the modeling of Three-Level converter according to critical characterist.

This paper presents a detailed small-signal and transient analysis of a Three-Level zero-voltege-switched PWM converter designed for high voltage, high power applications using an average model.

A impedance model simulating the electrical characteristics of the Electrodeless fluorescent lamp operated at high frequency is proposed. The model is constructed from a two parameter equation which is derived based on a set of two measurements. This is a readily constructed and computer simulator oriented model which is suitable for a preliminary design of electronic ballasts. Simulated and experimental results arc used to verify the analytical discussions, and, moreover, an electronic ballast design example using the proposed model is presented to further demonstrate its applications.

This paper proposed a new driving method for the stable lighting of CDM lamps. To avoid the acoustic resonance in the proposed method, the inverter output voltage will be a low frequency rectangular waveform containing a sinusoidal voltage ripple with high frequency. Moreover, the realtime power control of the inverter can be achieved by the control of switching currents. To verify the validity of tile proposed method, a prototype set-up was build and the experimental results are presented in this paper.

As car industry takes the DMB, geographical feature information and Internet service recently, the need of an electricity energy is the trend to increase. But existing 12V car electricity system is difficult to be satisfied rapidly increasing electricity need. A relation component company is adding the spur at a high electricity system development. In this paper we accomplished the hi-directional DC-DC Converter for high electricity system composed 42V configuration device. Through a simulation experiment, We looked into the control method and the operation characteristic of the circuit, We accomplished the comparison analysis for fit topoloy selection.

SFC(Static Frequence Converter)system has come to be used as start-up drive system for large synchronous machine in many industry applications. Many papers have been presented the control algorithm for pumped storage power generation using SFC system but they did not included about the detailed start-up algorithm of gas turbine using SFC system. This paper presents the important field weakening control algorithm of a large synchronous machine using SFC system and the results of experiment show that the proposed algorithm is proper and effective about this.

KEPRI developed digital excitation system for San-Cheong pumped storage power plant. This is the very complicated system because of operation connected with SFC(Static Frequency Converter). Many operation modes(stating, regeneration, back to back, line charging, gird connection mode etc) during the commissioning were successfully tested at san-Cheong #2.

For the life extension of Jeju thermal power plant, digital PWM excitation system was replaced by KEPRI. This system consist of TMR(Triple Modular Redundant) controller, dual PWM power inverter for field current control and MMI etc. The Performance test during the commissioning verified the reliability of digital PWM excitation system and recently, this system has been operated successfully.

In this paper, a static var compensator using three phase PWM Watkins-Johnson AC-AC converter is presented. The PWM Watkins-Johnson AC-AC converter is modelled by using circuit DQ transformation whereby the basic DC characteristics equation is analytically obtained. Finally, the PSIM simulation shows the validity of the modelling and analysis.

본 논문은 AC PDP 서스테인 회로에서 가장 보편적으로 사용되어지고 있는 Weber 회로를 비롯하여 최근 들어 가장 주목을 받고 있는 3가지 변형된 Weber 회로에 대한 이론적 동작 설명과 각각 회로에 대한 장, 단점 그리고 실험 및 시뮬레이션 파형에 대한 비교, 분석을 하였다.

서스테인 구동회로에 사용되는 전통적인 웨버 회로와 이 회로의 단점을 보완하고 비용절감을 위해 제안 되었던 회로들을 소개 한다. 이들 회로들을 AC PDP 응용 시스템에 적용하여 휘도, 소비전력, 효율에 관해 각 각의 장, 단점을 비교 하였다.

본 논문에서는 250W 메탈핼라이드 램프용 전자식 안정기의 구조 및 디밍 방법에 따른 특성을 비교하였다. 측정 및 분석된 안정기는 PFC, 벅 컨버터, Full-bridge 인버터의 3단 구조를 가진 안정기와 PFC, Half-bridge 인버터의 2단 구조를 가진 안정기이다. 3단 구조를 가진 안정기의 경우 벅 컨버터의 듀티 조절하여 출력 전력을 제어하며, 2단 구조 안정기의 경우는 구동 주파수를 조절하여 전력을 제어한다. 본 논문에서는 각각의 전력제어 방식을 통한 램프 디밍 시의 출력의 특성을 측정 및 분석하였으며, 조도 조절 범위는 $100%{\sim}35%$까지 구현하였다.

환경 친화적인 자동차, 안전한 자동차, 편리하고 편안한 자동차 등에 대한 다양한 요구에 효과적으로 대응하기 위해 기존의 기계/유압식 자동차 부품들을 전기장치로 대체하기 위한 연구가 꾸준히 진행되고 있으며, 특히 반도체 기술의 발전에 의한 가격경쟁력 강화에 힘입어 신규부품 개발 분야를 중심으로 자동차 부품의 전기/전자화가 급격히 진행되고 있다. 이에 따라 자동차에서 사용되는 전기에너지의 소요도 지속적으로 증가하여 새로운 차량용 전원체계에 대한 연구, 개발의 필요성이 대두되었고, 1990년대 중반 미국의 MIT/Industry Consortium 등을 중심으로 선행연구가 진행되어 자동차용 42V 전원체계가 새로운 대안으로 제시되었으며, 아울러 연비개선을 위한 마일드 하이브리드 기능의 채용이 검토되었다. 본 논문에서는 42V 전원체계 및 마일드 하이브리드 시스템 성능 구현에 핵심적인 역할을 하는 에너지 저장시스템에 관해 소개하고, 마일드 하이브리드 운용에 적합한 에너지 관리장치 개발에 대해 간략히 소개하고자 한다.

In this paper, analysis of BLDC motor torque ripple characteristic according to current commutation angle. The ideal rectangular current wave and the trapezoidal current wave by current commutation angle and BLDC back-EMF are analyzed mathematically using Fourier series. Moreover, the simulation is performed by Matlab/simulink to compare with experiment results and analyze BLDC motor characteristics.

본 논문에서는 고압전동기를 직접 드라이브 할 수 있는 H-브릿지 멀티레벨 인버터를 제안한다. 전동기의 부하장치로는 에디커런트 다이나모메타를 사용하였다. H-브릿지 멀티레벨 인버터는 여러 개의 단상 Power Cell을 직렬로 연결함으로써 저전압 전력용 반도체를 사용하여 고전압을 얻을 수 있고, 정현파에 가까운 출력전압 파형을 얻을 수 있는 멀티레벨 인버터 토폴로지이다. H-브릿지 멀티레벨 인버터의 주요 장점은 Power Cell의 모듈화, 셀 단위의 보호동작 용이, 확장성 향상 그리고 제어 신호 및 Power Cell의 신뢰성 향상에 있다. 본 논문에서 제안하는 H-브릿지 멀티레벨 인버터는 상당 3개의 Power Cell이 직렬로 연결되어 총 9개의 Power Cell로 구성이 되어, 선간전압은 13레벨이며 dv/dt가 적으며 입력 단 THD를 크게 낮출 수 있다. 정격용량 180kVA 이고 출력전압이 480V인 H-브릿지 멀티레벨 인버터를 제작하여 와전류 다이나모메타 부하 시험을 통해 제안된 방법의 타당성과 신뢰성을 입증하였다.

본 논문에서는 대용량 전력 변환 장치이며 출력 전압 가변이 가능한 H-브릿지 멀티레벨 인버터의 제어 알고리즘을 제안한다. H-브릿지 멀티레벨 인버터는 독립적으로 절연된 직류 부를 갖는 저압의 단상 인버터(셀 유닛)를 다수 직렬 접속하여 고압 3상 전압을 출력하는 Cascaded H-bridge 전압형 인버터이다. 다수의 독립 절연 직류부를 만들기 위해 입력 측에 다권선 변압기를 사용하여 입력 측 고조파 함유율을 축소시킬 수 있다. 인버터를 사용하는 제어방법 중 가장 오래되고 일반적인 방법으로 출력전압과 출력 주파수의 비를 일정하게 제어하여 전동기의 자속 크기를 일정하게 제어하고, 별도의 센서 없이도 운전이 가능한 V/F 제어모드는 저속 모드에서 제어 성능이 떨어지는 것을 실험을 통해 확인할 수 있었다. 정격용량 180kVA이고 출력 전압 480V인 H-브릿지 멀티 레벨 인버터 실험을 통해 벡터제어와 센서리스 벡터제어를 구현하여 저속 모드에서 제어 성능의 향상을 입증하였다.

선형전동기와 같은 선형운동을 하는 기기에서 원형운동을 하는 경우 속도가 0 이되는 부분에서 비선형적인 마찰력이 작용하며 이로 인한 운동괘적의 외곡 현상이 발생한다. 본 연구에서는 이러한 마찰력을 비롯한 모든 외란을 하나의 비선형적인 외란으로 간주하여 실용적으로 사용할 수 있는 간단한 형태의 외란 관측기를 제시한다. 또한 모든 외란 관측기에서 피할수 없는 문제의 하나인 전동기 관성(모멘트)의 변동 문제를 해결하기 위하여 제한적이지만 매우 효과적으로 관성을 추정해낼 수 있는 새로운 방법을 제안한다.

Recently, Peoples are exposed the ELF(Extremely Low Frequency) magnetic fields in the vicinity of underground transmission lines, and there are the generally accepted opinion that the magnetic fields affect the human body and there are possibility of the disease. Also in relation to this problem, technical solution methods and research are advanced for reducing the magnetic fields. In this paper, to practically understand the magnetic fields underground transmission lines, We analyze the electromagnetic field distribution in the underground transmission lines by means of FEM(Finite Element Methods) and present that improvement of the effective shielding methods by applying cable arrangements and shielding materials, eddy current problem to the underground transmission lines by means of the numerical analysis Tool.

전력변환 장치에서 기존의 PID 제어기의 해석적인 해를 얻는 것은 매우 어려운 일이다. 최근에 단상 UPS용 인버터 시스템에서 CRA 기법을 이용한 새로운 제어알고리즘을 바탕으로 시스템의 제어기의 제어상수를 해석적으로 접근하여 좋은 성능을 얻은 바 있다. CRA 기법은 해석적으로 시스템의 응답속도 및 오버슈트를 임의의 제한범위 내로 설계할 수 있도록 하는 장점이 있다. 이러한 CRA 기법을 사용하여 컨버터 제어기 설계부분에 적응하여 해석적인 해를 얻고 PSiM 시뮬레이션을 통해 오버슈트와 빠른 응답을 확인한다.

This paper deals with an analysis and design of the state feedback current controller's gain in the three-phase current control systems. First, this paper derives the transfer function of the closed loop current control system and also compares the state feedback current controller with the conventional proportional integral controller. A new pole placement method by using the pole/zero cancellation method is proposed to give a simple and concrete concept with respect to the pole selection. Experimental results on the permanent magnet synchronous motor show that the proposed method is very useful to design the gain of the state feedback current controller.

This paper presents control algorithms for unified active power filter. The algorithm is based in the performance function. The performance function is defined, and the compensation voltage reference is calculated for harmonics voltage and the compensation current reference is calculated for power factor. The proposed control algorithm can be applied to 3-phase 3-wire system and has a superior compensation characteristics for both harmonic current sources and harmonic voltage sources.

준공진형 플라이백 컨버터를 사용하여 Full HD급 DLP 프로젝터용 컨버터 설계에 대해 고찰하였다. 소형 경량화 시키기 위한 방법으로 Full Mode Packaging 형태로 절연설계에 유리하게 하였고, Shidegn사의 MR4040을 사용하여 부분공진 스위칭 동작에 의해 고효율 저노이즈를 실현하였다. 중부하 시 스위칭 주파수는 35KHz, 경부하시 스위칭 주파수는 최대 200KHz이고 입력전압 AC $90{\sim}264$[v], 출력전력 66W급의 컨버터을 제작하였으며 측정된 효율은 최고 93% 이다.

The ultrasonic welding is with features of high electric conductivity and hot conductivity when it is used in metallic bond, high electric conductivity and hot conductivity when it is used in various metallic bonds, excellent quality when it is used for advanced junction, easiness when it is used in various metallic bonds, being needless for the exhaustive material and being benefit for the environment. Currently the use of ultrasonic welding is increasing in the industrial fields such as the automobile battle, the refrigerator, the air conditioner, the battery and the solar cell junction. But the production ability is insufficient in our country and it is necessary to explore the core technology of the ultrasonic welding. In this paper, the output LC resonance filter and 35kHz squal wave onion occurrence Full Bridge plans was designed. The output examination of the ultrasonic oscillator and the ultrasonic welding examination were done. The method for getting more smooth result in the ultrasonic welding machine system was researched.

본 논문은 우리나라와 같은 안정된 계통(Strong Grid)에서 계통전압이 한전배전계통 공급기준의 전압변동률 ${\pm}6%(220V{\pm}13V)$이내에서 변화할 경우 계통 역률이 0.9 이상이고 부하전압의 변동이 거의 없도록 계통 연계형 전압제어형 전압원인버터(VCVSI)에 적합한 최대 전력제어각과 각각 최적의 시스템 용량(계통, 디커플링 인덕터, VCVSI)을 구하고, 유효전력을 100% 공급하기 위한 파라미터 설계 방법을 제시하였다.

본 논문에서는 계통연계형 인버터에서 요구되는 전력품질 개선 기능, 부하수요관리 기능, 무정전전원공급 기능 등을 전류제어형 전압원 인버터 시스템에서 통합적으로 수행할 수 있는 UPS를 고려한 계통연계형 전류제어 인버터를 제안한다. 제안된 시스템은 평상시에는 무효전력 보상, 고조파 저감, 부하수요관리 등의 PCS(Power Conditioning System) 기능을 수행하고 계통 고장시에는 배터리에 저장된 에너지를 이용하여 부하에 즉시 정전압을 공급하는 UPS 기능을 수행한다. 본 연구에서는 제안된 시스템의 동작원리 및 제어 알고리즘을 이론적으로 해석하고 시뮬레이션을 통하여 유용성을 확인한다.

This paper presents a grid-connected photovoltaic (PV) system with direct coupled power quality control (PQC) algorithm, which uses an inner current control loop (PRT : polarized ramp time) and outer feedback control loop to improve grid power quality and maximum power point tracking (MPPT) of PV arrays. To reduce the complexity, cost and number of power conversions, which results in higher efficiency, single stage CCVSI (Current Controlled Voltage Source Inverter) is used. The proposed system operation has been divided into two modes (sunny and night). In night mode, the proposed system operates to compensate the reactive power demanded by nonlinear or variation in loads. in sunny mode, the proposed system performs PQC to reduce harmonic current and improve power factor as well as MPPT to supply active power from the PV arrays simultaneously. it is shown that the proposed system improves the system utilization factor to 100% which is generally low for PV system (20%). To verify the proposed system, a comprehensive evaluation with theoretical analysis and simulation results are presented.

본 연구에서는 조명기기의 에너지 절약 및 전력품질 개선 기능을 갖는 다기능 에너지 절약 시스템을 제안한다. 제안된 시스템은 부하의 적정전압을 유지하기 위한 전압제어형 인버터와 계통의 고조파 저감 및 단위역률 제어를 위한 전류제어형 인버터가 병렬로 연결된 형태로 기존의 단권 변압기를 이용하는 절전 장치의 탭 절환시의 스파이크 및 변압기 소음 문제 및 반도체 소자에 의한 절전장치의 에너지 회생문제를 해결할 뿐 아니라 전압제어형 인버터의 용량은 정격부하의 약 10%이내이며, 전류제어형 인버터의 용량은 정격부하의 약 30%이내로 시스템의 소형 경량화 및 가격하락의 장점을 가진다. 본 연구에서는 기존의 절전장치들의 문제점을 이론적 해석 및 실험을 통하여 설명하고 제안된 시스템의 동작원리 및 제어 알고리즘을 설명하고 시뮬레이션을 통하여 시스템의 유용성을 확인하였다.

포항가속기 연구소의 선형가속기에는 22개의 솔레노이드 전자석, 16개의 사극전자석 그리고 전자빔의 궤도 조절을 위한 16개의 2극 전자석이 있다. 선형가속기의 빔을 저장링으로 공급해주는 빔 전송선에는 22개의 사극전자석과 13개의 빔 궤도 조절용 이극 전자석이 있다. 전자빔의 정밀 제어를 위하여 전자석의 전원장치는 출력전류 분해능은 16bit 이상이고 출력전류의 안정도는 최대출력에 대하여 ${\pm}50ppm$ 이하의 고정밀 고안정도가 요구된다. 이를 위하여 풀-브릿지 4상한 DC/DC 컨버터를 이용한 전자석전원장치를 개발 하였다. 전원장치의 입력전압 직류 40V이고 출력전류는 단방향 전원장치는 최대 50A/50V 이고 양방향 전원장치는 ${\pm}20A/20V$이다. 스위칭 주파수는 50 kHz이다. 전원장치의 출력부에 필터가 없으면 출력전류에는 스윗칭과 관련된 주파수 성분이 포함 되고 전자빔은 이들 주파수 성분에 대하여 영향을 받게 된다. 이러한 이유로 출력 필터의 cut-off 주파수는 5 kHz 이하가 되어야 한다. 본 논문에서는 고정밀 고안정 스윗칭 전자석전원장치를 위한 출력필터의 설계, 제작 그리고 이를 적용한 전자석전원장치에 대하여 논의 하고자 한다.

In this paper, an DC/DC converter system has been proposed, which is suitable for fuel cell based power generation systems. The proposed converter system has outstanding advantages over the conventional dc-dc converters with respect to high efficiency and high power density. The developed converter system has been experimentally tested with using DSP PWM controller so that the performance of the proposed converter could be effectively examined and the validity of the converter could be verified.

Power line communication: PLC which easy to install at anywhere near outlet for electric machine. PLC uses transmission line for voltage of which is 60 Hz. One of the important thing is the processes of adding signal to power line and extracting the signal from power line, another is to choose the strong modulation method which sends signals to long distance without loosing in PLC channel. but PLC channel have very high and variable noise and attenuation and then it is very hard to transmit optimally between the transmitter and the receiver. AWGN, impulse noise and attenuation are created. To overcome the noise and attenuation. Multi-carrier Modulation methods like as OFDM and DMT which divide the channel into many sub-channel are powerful communication methods for PLC. In this paper, PLC channels are simulated for getting BER by Matlab simulink

This paper investigates a speed sensorless control of induction motor. The control strategy is based on MRAS (Model Reference Adaptive System) using load-torque observer as a reference model for flux estimation. The speed response of conventional MRAS controller characteristics is affected by variations of load torque disturbance. In the proposed system, the speed control characteristics using a load-torque observer control isn't affected by a load torque disturbance. Simulation results are presented to prove the effectiveness of the adaptive sliding mode controller for the drive variable load of induction motor.

An active-clamp current-fed push-pull converter for the step-up application is proposed. The proposed converter is composed of active-clamp circuits and a voltage doubler rectifier. Thus, the voltage stress of the main switches is reduced and the output diodes are clamped to output voltage. Moreover, the output diodes can achieve zero current switching (ZCS) by the series resonance between resonant capacitors and leakage inductances. The prototype is designed for 350V/1.5kW with input voltage range $30{\sim}60V$. The theoretical analysis and experimental results are presented.

There is an application which uses smoothing reacter connecting each of the phases in order to make the system smaller comparison with an application using the insulating transformer in the utility interactive photovoltaic generation system using the PWM converter. In this case, there might be the occurence of the unbalance of output voltage, by the difference of smoothing reactor, connected on each of the lines. Therefore this study proposes that the method which maintains the balance and compensates the unblance which occured by the different volume of the smoothing reactor connected on each of the lines.

A new soft switched active snubber circuit is proposed to achieve zero voltage and zero current switching for all the switching devices in PWM DC-DC converters. The unique location of the snubber capacitor and inductor ensures low current/voltage stresses and commutation losses. With a saturable reactor, the conduction loss of the auxiliary switch could be further minimized. A boost converter adopting this technique is presented as an example, to illuminate its operation principles and derive the design procedures. Simulation and hardware implementation have been made to validate its performance. Some other basic PWM DC-DC topologies using the proposed snubber have also been given.

Marine technology must advance to meet the needs of a wealthier and more demanding public while at the same time provide greater environmental protection. Pollution noise and vibration is the specific issue being discussed in this paper Noise is of course due to vibration from high speed engines driving generators, entilators, winch and other gear, while underwater noise pollution results from the propellers and the resistance produced by the hull of the ship moving through the water. Vibration is also a factor in potential damage to sensitive electronic gear and metal fatigue. The issue of noise pollution does not cease when a vessel enters her berth and the main engines shut down. There is still the matter of ventilation and other mechanical factors at work to maintain a comfortable, efficient environment. We measured the noise level and vibration displacement in the training ship A-Ra at underway and Berth. The authors analyzed the frequency of noise and maximum vibration displacement in the position.

In this paper, a new single phase voltage sag/swell compensator using direct power conversion is introduced. A new compensator consists of input/output filter, series transformer and direct at-ac converter, which is a single-phase back-to-back PWM converter without dc-link capacitors. Advantages of the proposed compensator include: simple power circuit by eliminating dc-link electrolytic capacitors and thereby, improved reliability and increased life time of the entire compensator; simple PWM strategy to compensate voltage sag/swell at the same time and reduced switching losses in the ac-ac converter. Further, the proposed scheme is able to adopt simple switch commutation method without requiring complex four-step commutation method commonly required in the direct power conversion. Simulation results are shown to demonstrate the advantages of the new compensator and PWM strategy.

프로세스 제어기에서 전원장치의 건전성과 신뢰성은 아무리 강조해도 지나치지 않을 것이다. 본 논문은 전원장치의 고장 감시장치에 관한 것으로, 직류 전원공급 시스템의 신뢰도 향상을 위하여 사용하는 이중화 전원 구성용 블로킹다이오드의 고장 감시 장치에 관한 것이다. 이중화 전원 공급장치에 있어서 2개의 공급전원 중 어느 한쪽의 공급전원이 상실되더라도 나머지 한쪽의 공급전원이 건전하면 정상적으로 부하에 전원을 공급하게 하기 위하여 블로킹다이오드를 사용한다. 그러나 블로킹다이오드에 고장이 발생한 경우, 전원공급장치 자체는 정상이더라도 이중화 기능을 하지 못하므로, 블로킹다이오드의 정상 여부를 상시 감시하여 이상이 발생시 경보처리 한다면 예기치 않은 전원공급 중단을 피할 수 있을 것이다. 블로킹다이오드에 흐르는 전류와 다이오드의 양단 전압을 상시 감시/계측하여 정상운전특성곡선과 비교하여, 이상이 있을 경우 이를 경보하여 전원중단을 예방할 수 있는 이중화 전원용 블로킹다이오드의 고장 감시 장치에 관한 것이다.

BLDC(Brushless DC) 전동기는 브러시(brush) 방식 DC 전동기의 브러시와 정류자를 반도체 소자를 이용한 인버터로 대체한 것으로 높은 효율과 제어의 용이성 때문에 최근 많이 사용되고 있다. 하지만 회전자의 위치 정보에 의해 정류를 하므로 회전자 위치 센서가 필요하고 그에 따라 전동기의 구조가 복잡하게 되고 작동 환경에 제한을 받게 된다. 본 논문에서는 위치 센서 없이 고정자의 권선에 유기되는 역기전력을 이용한 센서리스(sensorless) BLDC 전동기의 토크리플 저감에 대하여 연구하였다. BLDC 전동기를 수학적으로 모델링하여 센서리스 BLDC 전동기의 토크리플 제어 알고리즘을 구성하고 시뮬레이션과 실험을 통하여 그 결과를 검토하였다. 또한 기존 센서 부착형 BLDC 전동기와 비교하여 그 타당성을 입증하였다.

전력용 능동 필터를 제어하기 위해서는 보상 고조파 전류에 대한 지령치가 필요하다. 3상 전력용 능동 필터의 경우 순시전력이론을 이용하여 보상 전류 지령치를 계산할 수 있다. 하지만 단상 전력용 능동 필터의 경우에는 디지털 필터를 사용하는 것이 일반적이다. 디지털 필터의 차수가 높은 경우에는 필터의 성능이 향상되지만 높은 차수에 따르는 연산시간의 증가와 민감도 증가로 인하여 설계 조건에 부합하는 저차 디지털 필터의 설계가 필요하다. 본 논문은 제안된 notch filter 설계 기법으로 디지털 필터를 설계하고 제어루프에 필터 사용시 발생 할 수 있는 안정도 저하를 평가하고, 시뮬레이션을 통하여 그 성능을 검증하였다.

본 논문에서는 MATLAB/SIMULINK와 dSPACE DS1104보드를 이용하여 유도전동기의 간접백터제어 알고리즘을 구현하였다. 유도전동기의 간접벡터제어를 위한 전체 시스템 모델은 SIMULINK 그래픽 모델과 dSPACE DS1104 R&D Control 보드의 Real Time Interface(RTI)를 이용하여 구현한 후에 실험을 수행하였다. 벡터제어를 위해서 전동기 전류의 측정은 16kHz로 측정하였고, 측정된 전류를 이용하여 8Hz로 전류제어기, 4kHz로 속도제어기를 구현하였다. MATLAB과 dSPACE 보드의 컴파일러가 설계된 그래픽 모델의 C source 파일과 object 파일을 자동으로 생성시켜주기 때문에 추가적인 프로그램의 coding 없이 실제 시스템의 시뮬레이션과 실험을 동시에 수행할 수 있으며 원하는 제어성능을 얻을 수 있다.

This paper designed a robust control of an induction motor using a disturbance cancellation observer of a feedforward control. The speed response of conventional PI controller characteristic is affected by variations of load torque disturbance. In the proposed system, the speed control characteristic using a feedforward control isn't affected by a load torque disturbance. High speed calculation and processing for vector control is carried out by ADMC300 digital signal processor. Validity of the proposed control method is verified through simulation and experimental result.

In this paper, design of current and speed controller for DC motor drive system using Embedded Target for TI C2000DSP in Matlab/Simulink is introduced. Current and speed controller is designed and implemented using program simply and easily, and speed control response of DC motor can be advanced. Current and speed control of DC motor is carried in eZdsp F2812 control board using Embeded Target for TI C2000DSP in Matlab/Simulink. Speed feedback is processed through A/D converter using tacho generator as speed sensor, and current feedback is processed through A/D converter using hall sensor as current sensor. Controller is designed to PI current controller and PI speed controller. Current and speed response is verified through simulations and experiments.

본 논문에서는 리얼게인사의 DSP를 사용하는 고속설계시스템에 의한 부하토크관측기 및 속도 제어기의 설계에 대하여 소개한다. 고속설계시스템은 CEMTool/SIMTool 소프트웨어 프로그램과 RG-DSPIO 제어보드, AUTOTool 프로그램으로 구성되어 있고 이것을 DC Motor 구동시스템에 사용하였다. SIMTool 블록들을 사용함으로써 짧은 시간동안에 다양한 형태의 제어기를 설계 및 구현할 수 있도록 해주는 장점이 있기 때문에 DC Motor의 부하토크관측기 및 속도제어기를 제어 목적에 따라서 쉽게 설계하고 구현할 수 있다.

In this study, in order to solve these problems, a new type of electronic ballast, which is composed of rectifier, active power factor corrector, series resonant half bridge inverter and piezoelectric transformer, was proposed for driving T5 fluorescent lamp. Driving of piezoelectric transformer was carried out with input region for the ring electrode and output region for the dot electrode. A 35W (T5) fluorescent lamp was successfully driven by the fabricated ballast with piezoelectric transformer.

In this paper, I used microprocessor and sensor and designed to improve the efficiency of the photovoltaic system the photovoltaic position tracker device, and compared the normal photovoltaic system of fixed form with the photovoltaic system of solar position tracked form. Moreover, compared the catalogue of solar cell module and the simulation through a mathematics modelling with the solar cell's characteristic interpreting and, composed an power conversion system with boost converter and voltage source inverter. Used the constant voltage control method for maximum power point tracking in boost converter control and, used the SPWM(Sinusoidal Pulse Width Modulation) control method in inverter control.

CFL(Compact Fluorescent Lamp)는 기존에 사용되던 백열 램프를 바로 대치할 수 있고, 백열 전구에 비하여 광 효율이 우수하다는 장점으로 인해서 사용처가 점점 증가되고 있는 추세이다. 하지만 등기구가 가지는 공간적인 제약으로 인해서 EMI 필터와 PFC 회로를 내장할 수 없으며, 램프에서 발생한 열이 직접적으로 안정기 회로에 영향을 주어 안정기 내부 온도가 매우 높게 상승한다는 점으로 인해서 다양한 기능을 갖는 전용 ballast control IC를 사용할 수 없었다. 이러한 이유로 인해서 toroidal core를 이용한 자려식(self-excited) 동작 방법이 주로 이용되어왔다. 이러한 자려식 발진 방법은 설계하기가 까다롭기 때문에 램프 점등 전에 램프 필라멘트를 예열한 이후에 점등을 하는 rapid start 방법을 구현하기 어려웠다. 본 논문은 fairchild 반도체에서 만든 CFL 전용 ballast IC가 가지는 특성에 대해서 다루었다. IC 내부에 안정기 동작을 제어하기 위한 제어 부분과 두 개의 MOSFET를 내장하고 있어 안정기 구성에 필요한 공간을 최소화할 수 있고, 부하 상태를 검출하여 항상 Active ZVS 동작을 하도록 하는 기능을 내장하고 있어서 스위칭 손실을 최소화할 수 있다는 장점을 가지고 있다.

The resonant converters cause the high voltage stress according to the input voltage, which increases the conduction loss in converter power switches. The topology of LLC half bridge resonant converter provides ZVS characteristic and also the stress of voltage and current is not higher than that of the general resonant converters. So we can expect the higher efficiency. In this paper, the LLC resonant converter is designed for the notebook computer adapter. In the adapter design, we should consider the weight, the size and overheat of the adapter. Thus the higher efficiency is an essential particular. First of all, the optimal design of transformer is the most important facts. Some parameters should be considered in order to get the highest efficiency. The adapter is designed through the considering of these parameters including the PFC circuit of the pre-regulator. It converts AC line input into about $400V_{DC}$ Link voltage of the LLC converter input and the converter has $16V_{DC}/90W$ ratings. The efficiency measured is about up to 92%.

본 논문은 전동기에 유입되는 전력을 사용한 매트릭스 컨버터 드라이브의 센서리스 제어에 대한 새롭고 간단한 방법을 소개한다. 제안하는 제어 알고리즘은 유도 전동기에 흐르는 순시 유효전력과 무효전력을 제어하는 것을 기반으로 한다. 저속의 센서리스 성능을 향상시키기 위해, 정류 지연, 스위칭 소자의 동작횟수, 그리고 온-상태에서의 스위칭 소자의 전압강하 등이 PQ-전력변환과 기준전력 제어기법을 이용하여 설계한다. 제안하는 센서리스 제어 방법은 3kW 매트릭스 컨버터 시스템 기반의 유도전동기 구동장치에 적용하고 제안한 제어 전력의 실현 가능성을 보여준다.

본 논문은 전동기의 일정한 공극자속과 전동기에 유입되는 무효전력을 이용한 매트릭스 컨버터 구동장치의 새롭고 간단한 센서리스 기법을 제안한다. 저속의 센서리스 성능 향상을 위해 정류지연, 스위칭장치들의 턴-온, 턴-오프시간 그리고 스위칭장치의 온-상태에서 전압강하와 같은 매트릭스 컨버터의 비선형성을 PQR 전력변환을 이용하여 모델링하고 기준 전류제어기법을 이용하여 보상한다. 3 kW급의 매트릭스 컨버터 구동시스템에 적용하여 제안된 센서리스 기법의 타당성을 검증한다.

최근 반도체 및 FPD 산업에서 Glass의 사이즈, 무게의 증가함에 따라 물류 이송 장비의 전원장치인 비접촉 전원장치의 크기와 용량이 증가하는 추세이며, 또한, 클린룸의 규모가 커짐에 따라 물류 이송 장비 시스템의 길이가 길어지고 Vehicle의 수가 증가하는 추세이다. 본 논문에서는 여러 대의 Vehicle간 독립제어가 가능하고, 물류 이송 장비의 구조가 직선부분과 곡선부분이 혼용되어진 구조에서도 사용 가능한 정전류 비접촉 전원장치의 주요 전력변환 토플로지 별 해로해석, 제어방법을 제시하였고 특히 직 병렬 공진 컨버터의 회로해석, 특성평가를 행하였다. 이 특성평가를 바탕으로 정전류 비접촉 전원장치의 시제품을 제작하여 저항성 부하와 선형 구동 시스템에 적용한 Vehicle 2대를 부하로 사용하여 실험을 행하여 실제 적용, 가능함을 보이고자 한다.

The DITC of SRM for smooth hoist driving is presented in this paper. In the hoist system, the switched reluctance motor (SRM) is applied instead of induction motor because of high efficiency and good traction characteristic. In order to improve start-up and stop performance of hoist system, the smoothing operation sequence of SRM using DITC is proposed. According to the switching sequence and hysteric band, the instantaneous torque is controlled. Since, the proposed method uses only the turn-on angle depending on variation of load and speed, a simple DITC can be implemented. The validity is proved by simulation and experiment.

This paper is proposed to a novel DC-DC converter operated high efficiency for loss-less snubber capacitor. The general converters of high efficiency is made that the power loss of the used switching devices is minimized. To achieve the soft switching operation of the used control switches, the proposed converter is constructed by using a loss-less snubber capacitor. The proposed converter achieves the soft-switching for all switching devices without increasing their voltage and current stresses. The result is that the switching loss is very low and the efficiency of converter is high. The soft switching operation of the proposed converter is verified by digital simulation and experimental results.

This paper deals with mathmatical of an induction motor, considering non-linearity in the torque balance equation under closed loop operation with a reference speed. A controller based on Adaptive Nuro-Fuzzy Inference System (ANFIS) is developed to minimize overshoot and settling time following sudden changes in load torque. The overall system is modeled and simulated using the Matlab/simulink and Fuzzy Logic Toolbox. The advantages of fuzzy logic and neural network based fuzzy logic controller. Required training data the ANFIS controller is generated by simulation of the anti-windup PI controller is eliminated using the ANFIS controller. The transient deviation of the response from the set reference following variation in load torque is found to be negligibly samll along with a desirable reduction in settling time for the ANFIS controller.

독립형 연료전지 전력변환 시스템에서 인버터는 출력주파수의 2배 성분의 리플을 가지고 있기 때문에 직류버스 전압에도 이 주파수 성분이 존재하게 된다. 이 리플 전류는 연료전지의 수명과 효율을 저하시키므로 제어기를 통해 줄여야 한다. 최근 특성비 지정법을 이용하여 해석적으로 기어기를 설계하는 방법이 제안되었다. 해석적인 방법으로 연료전지 인버터의 제어기를 설계한다. 이 제어기는 부하 변동에 대해서 응답속도가 빠르며 120 Hz 리플에 강인함을 확인한다.

This paper presents a remote dimming control method for the electrodeless lamps using 2.4 GHz RF communication. Since the proposed dimming method are implemented with a simplest open loop control using ISM band HF modem and low cost MCUs, and the remote controller has just several functions such as On/Off and duty ratio increasing/decreasing. It can be made with low cost. In this paper, the detailed digital logics of the proposed remote dimming control are described and the experimental results are presented.

In this paper, the proposed power supply is based on a modified version of the zero-voltage switching(ZVS) full-bridge phase-shift DC-DC converter, which incorporates commutation auxiliary inductors to provide ZVS for the entire load range as well as a commutation aid circuit to clamp the output diode voltage. The control strategy is based on two control loops operating in cascade mode. The complete operating principles and simulation results in presented.

In this study, vibration mode multilayer piezoelectric transformer was designed and thickness simulated using ANSYS of finite element method simulator for investigating its optimum conditions ist. As a results, resonant frequency was decreased with the increase of output layer thickness, Output voltage, maximum displacement and maximum stress at 0.34mm thickness transformer were 228.1 V, $0.42{\mu}m,\;8.78[N/m^2]$ respectively.

This paper represent improved On-line Turn off, commutation Angle control schemes for switched reluctance motors based on current control. For the purpose of the finding optimal commutation switching angle point, it is utilized turn on and turn off position calculation with inductance vs. current vs. flux linkage analysis method. The goal of proposed paper is the maximization of the energy conversion per stroke and maximizing efficiency and obtaining approximately flat-topped current waveform. The proposed control scheme is demonstrated on a simulation experimental result.

본 논문에서는 곡선구간에서도 구동이 가능한 선형 전동기 제어방법을 제안하였다. 곡선구간에 선형 전동기를 적용할 때 전동기의 고정자와 이동자의 기구적인 위치 상호관계에 의해 각 상의 위상관계는 직선구간과 다르게 나타나게 된다. 따라서 직선구간의 제어방법을 그대로 곡선구간에 적용 시 제어성능이 저하되어 전동기의 발생추력은 감소하게 되고, 최악의 경우 곡선구간에서 구동이 불가능한 상태가 된다. 이러한 문제점을 개선하기 위하여 전동기의 역기전력 정보로부터 위상정보를 추출하여 곡선구간의 구동 제어알고리즘에 반영하였고, 제어시스템을 구성하여 곡선구간에서 전동기의 구동성능이 개선됨을 보인다.

The multi-resonant converter minimizes the parasitic oscillations using the resonant tank circuit absorbed parasitic reactances in a converter. So the converter can be operated at a high frequency and it provides a high efficiency because the switching power losses are reduced effectively. However, the high resonant voltage stress of semiconductors leads to the conduction loss. In this paper, it is proposed the novel flyback multi-resonant converter. The converter input is divided by two series input capacitors. And also the resonant stress is reduced to 2-3 times input voltage without any complexity and it provides the various circuit schemes in lots of applications. The proposed converters are verified through simulation and experiment.

This study is concerned with the control system design using Labview Simulation Interface Toolkit and Matlab/simulink combined system for an application to the personal rapid transit system which has very short headway, requiring accurate speed control to avoid the impact between the vehicles. A simple equation of motion for a vehicle which is activated on the linear motor is introduced. A speed profile that should be tracked by a rear vehicle is produced based on the state information of the two vehicles(the preceding vehicle and the rear vehicle). The speed profile tracking control system is designed by Matlab/simulink. The simulation results show that the proposed control system is effective to evaluate the speed tracking performance.

Maglev using EMS becomes unstable by unexpected big air-gap disturbance. The main causes of the unexpected air-gap disturbance are step-wise rail joint and large distance between rail splices. For the stable operation of the Maglev, the conventional system uses the threshold method, which selects one gap sensor among two gap sensors installed on the magnet to read the gap between magnet and guide rail. But the threshold method with a wide bandwidth makes the discontinuous air-gap signal at the rail joints because of the offset in air gap sensors and/or the step-wise rail joins. Further more, in the case of the one with a narrow bend-width, it makes Maglev system unstable because of frequent alternation. In this paper, a new method using fuzzy rule to reduce air-gap disturbances proposed to improve the stability of Maglev system. It treats the air-gap signal from dual gap sensors effectively to make continuous signal without air gap disturbance. Simulation and experiment results proved that the proposed scheme was effective to reduce air-gap disturbance from dual gap sensors in rail joints.

In this paper, we perform a simulation to verify the earth resistance values in Common Earth Network. The simulation is performed on the assumption that certain shorts are occurred in common earth network. Furthermore, from the result, we confirmed that very small earth resistance values in common earth network are given, by carrying out practical measurements in railway sections where common earth network is composed. From the effect, we could discover that the construction of common earth network is in a disadvantageous position on the financial aspect, while it is the most desirable way of construction for the purpose of Earth.

The wide spread of DC electric railway systems such as urban rapid transits including heavy rail and light rail transits has significant ramification as the stray currents from return conductor rails can cause the electrochemical interference, that is, the electrolytic corrosion of both rails and outside underground metallic infrastructures. The immature understanding of either the railway authority who is responsible for establishing the necessary provisions at the design stage or the affected parties makes it difficult to prepare the optimum range of solutions for the long-pending interference problem. In advanced countries, however, numerous assessment studies have been carried out on the stray current interference, by which protective standards and regulations are provided under the collaboration and agreement of the related parties. In this paper, we introduce a european standard from IEC, namely, "IEC 62128-2:2003 railway applications-fixed installations -part 2: protective provisions against the effects of stray currents caused by d.c. traction systems" and a "Code of Practice" produced by Victorian electrolysis committee (VEC) based on "Electricity Safety Act 1998" and "Electricity safety (stray current corrosion) regulations 1999" of Victoria state, Australia.

This paper presents circuit model of catenery in electrified railway system. Most of (a.c.)electrified railway system adopted as AT fed power supply system. This system is fed with twice voltage. It is that AT system can be fed through longer distance. Conventional circuit model of catenary is used T equivalent circuit with lumped parameter. This model may include some problem when traction power supply system is analyzed. In addition, the model with distributed parameter is good for analysis of harmonic and EMI.

This paper presents the methods to save energy by using load consumption pattern analysis. Base on the substation annual power usage data, the characteristic of the substation power consumption have investigated. With this investigation effective electrical billing condition and the control target load has been determined. Most of power usage comes from the motor car, so power system and load table of motor car were reviewed. And in the metropolitan area the peak power consumption occurs at summer or winter rush hours because of its typical characteristics. From this data control point of time are determined. Through the whole study the methode to control the power Peak consumption are proposed and prototype was designed.

The more feeding distance of substation is long and travel vehicle increases in feeding section, power supply leaches the limits. And if it exceeds the limit, it causes a serious trouble for train operation. Therefore, it is designed that the number of train increases constantly until 2030. So consistent power supply according to the increasement of vehicle in power system at present Seoul-Pusan high speed railway, regular operation in case of extended feeding occurring accidents in substation, and the least headway scheduled at relevant section and the effects installing compensation facility in case of impossible extended feeding is examined.

The wide spread of DC electric railway systems such as urban rapid transits including heavy rail and light rail transits has significant ramification as the stray currents from return conductor rails can cause the electrochemical interference, that is, the electrolytic corrosion of both rails and outside underground metallic infrastructures. The immature understanding of either the railway authority who is responsible for establishing the necessary provisions at the design stage or the affected parties makes it difficult to prepare the optimum range of solutions for the long-pending interference problem. In Japan, however, numerous assessment studies have been carried out on the stray current interference, by which protective guidelines are provided by "Electrolysis Committee". In this paper, we review a guide book from "Tokyo Electrolysis Committee", namely, "Protective Methods for Stray Current Corrosion".

EMU, Electric Multiple Unit, is very complicated system that consists of thousand parts. If breakdown happens, work that clears cause in most cases work that clears cause in most cases is very complicated and difficult. Also it needs much times and experts of several parts. Maintenance is depending on know-how of the operator and breakdown that happen before happens often repeatedly because information management and public ownership are not achieved properly about analysis and action result. In this paper we present the case-based expert system for EMU which is able to share this know-how knowledge that data-based systemically with another operator.

In this paper, the inductive power collector using electromagnetic Induction for vehicle such as the PRT(Personal Rapid Transit) system is suggested and some ideas for power collector design to improve the power transfer performance are presented. The inductive power of secondary part is related to amount of linked flux to secondary part by the length of air-gap, which is expected by such a system parameter as mutual inductance. This paper will study for the transfer characteristic of power from input to output and equation including mutual inductance.

This paper analyzes impedance convergence characteristics and harmonics of electric locomotives operation and fault condition. To simulate the various fault and operation condition, AT feeding system and various locomotives are modeled using PSCAD/EMTDC. Analysis shows that impedance are converged into protection area in the case of short fault between catenary and rail or catenary and feeder line but in the case of disconnection fault, impedance is rater bigger so protective relay can't detect the fault. Therefore more analysis of overload and high impedance fault caused disconnection fault is needed.

전력변환장치를 사용하여 열차를 추진하고 열차내에 필요한 전원을 생산하는 전기철도차량은 차량 내외부에 전자파를 발생한다. 차내 전자파는 제어에 영향을 미칠 뿐만 아니라 승객의 인체 건강에 영향을 주며 차외 전자파는 통신선이나 선로주변 전자기기에 영향을 주게 된다. 본 논문에서는 국내 기술로 개발한 한국형 고속열차를 대상으로 차외 전자파에 대한 시험을 EN50121 규격에 따라 수행하고 그 영향을 평가한다.

City Train Technology that is large and complex system and consists of mechanical, electronic, electric, materials, computer, communication, civil/track etc. is very important area of railway industry, national fundamental industry. The standardization of city train system as a public transportation method and foundation of national economy is very important in order to do effective operation and to get fundamental technology, and the information system of the standards is required to operate the city train system effectively. By building data base of city train system design knowledge using computer-aided system engineering tool-Cradle, the system development issues and the design solutions are used by all engaged persons, and are managed by modeling and documentation. And this system will support architecture design consistently and effectively by applying this system to formalize early development process, to system requirements and configuration management, to system interface analysis and management and to system behavior analysis etc.. This study is for construction of data base of system design knowledge through making data base of many kinds of standards using CASE tool based on System Engineering Process, and introduces a model to support concurrent engineering for all engineers involved in system development allowing access to standard DB through Web from anywhere and at anytime.

Configuration management plays a key role in systems engineering process for any project from earlier stage of development. It consists of five major activities, ie., configuration management planing, configuration identification, configuration control, configuration status accounting and configuration verification and audit, and is essential to control system design development and operation throughout entire life cycle of the system development. And it is directly associated with other part of systems engineering management, ie., technical data management which provides traceability of important decisions and changes during development. In this paper, we describe how to apply CASE(Computer-aided Systems Engineering) tool-Cradle for the configuration management to achieve effectiveness of City Train Standard Specification Management process.

This study investigated the needs and effectiveness of the application of Computer-Aided Systems Engineering Tool in order to enhance the chance of success of the large and complex system development projects like City Train System. Furthermore, it was shown that the merits of Systems Engineering and Project Management must be complementary to each other in their interaction in a project. Especially, for the project plans must be executed based on the fully understood system being developed, the technical and management data of the system development need be integrated and be able to support exact and rapid decision making of project planning. As an alternative solution approach, a model for development knowledge capture integrating both technical and management data of system development was proposed using Computer Aided Systems Engineering tool-Cradle.

The running of the electric train are done by powering, breaking and coasting. Powering to start and accelerate the rolling stock means driving the three-phase electric induction motors controlled by VVVF inverters which are connected to overhead power line directly(DC) or indirectly(AC, DC/AC). Breaking is achieved by blending control which is the proportional combination between regenerative breaking of VVVF inverter and air pressure control of breaking operating unit(BOU). Therefore, Data obtained during two operation are very important items to evaluate the running performance of RS. This paper has investigated in real time data acquired from VVVF inverter and measured by pressure sensor directly connected to air breaking line(motor car and trailer car). By analyzing data in the region of time and frequency, fundamental methods for eavaluating the running performance of RS quantitatively and objectively have been suggested.

In this paper, as a conceptual design of the catenary-current collection run tester which is planning to be constructed by KRRI, the feasibility study is described. In this study, reviews to determine the propulsion linear motor rating based on the target distance-speed curve through various simulation of LSM propulsion system were conducted. Moreover, the reviews of simulation results and desirable linear motor specifications are discussed in this paper.

This paper is described about the test equipment of fraction motor for electric train. This test equipment was able to perform the performance test of traction motor which was operated in Korea. We explain performance and function of test equipment. In order to check the performance of test equipment, we conducted the performance test with 200 kW and 1100 kW traction motor.

전기 자동차에서 회생제동시 회수되는 에너지의 양을 향상시키기 위한 회생제동 방식에 대하여 연구하였다. 회생제동시 에너지의 흐름중 밭전기의 효율이 최대가 되도록 토크과 모터 속도를 기어비를 제어함으로써 차량 제동시 보다 많은 에너지가 배터리로 회생되도록 하는 회생제동 최적변속 알고리즘에 대한 연구를 진행하였다.

본 논문에서는 교통 분야의 새로운 미래 성장동력분야 창출로 Global Standard도출하여 세계시장 선점 및 진출하자는 거대한 목표에 따라 IT기반의 네트워크 운행제어 시스템을 바탕으로 차량, 전력, 분기, 선로구축물 등의 하부시스템의 각종방식을 비교 및 검토하여 열차 시스템에 부합되게 선정하는 시스템설계를 수행하였다. 본 소형궤도열차시스템은 전세계적으로 영업운행 중인 노선이 없고, 운영 및 설계개념, 시스템 구성 등도 나라마다 상이하여 시스템의 개념정립을 통한 개발목표 사양(안)을 결정하는데 크게 참고가 될 만한 해외시스템이 많지 않은 실정이다. 따라서 본 연구에서는 이와 같이 제한된 참고자료와 경량전철시스템 기술개발사업에서 축적된 시스템엔지니어링 기술을 활용하여 첨단성, 친환경성, 경제성을 갖춘 소형궤도열차 시스템의 설계를 수행하였고 시스템을 구성하는 하부시스템을 정의하였다.

Tilting trains are now an established feature of railway operations throughout the world. For intercity traffic, tilt provides operators with increasing speeds, and therefore enhanced competitiveness, on existing routes where insufficient traffic or a lack of funds precludes the construction of a dedicated new high-speed railway. Appling the tilting train, we can expect 30% of speed up on existing lines, but the stability of the electric current would be low because of tilting the train. Also, the spark between the catenary and pantagraph cause environmental problems such as noise, radio wave malfunction. Therefore, the tilting on pantagraph for the power suppling device is very essential for stable electric power supply.

Tilting train has been developed to increase the operational speed of the trains on conventional lines which have many curves. This train are tilted at curves to compensate for unbalanced carbody centrifugal acceleration to a greater extent than compensation produced by the track cant, so that passengers do not feel centrifugal acceleration and thus trains can run at higher speed at curves. This paper show that results of normal capacity calculations of the electrical equipments such as Main transformer, PWM converter, VVVF inverter, traction motor in TTX(tilting train express) with maximum operation speed 180km/h

최근들어 열차의 고속화, 고성능화 추세에 맞는 철도의 안전성 확보가 더욱 필요해졌다. 이를 달성하기 위해서는 각 장치들에 대한 종합적인 시험평가가 이루어져야 한다. 특히 완성차 및 본선시운전 시험을 통해 차량에 대한 여러 상태를 확인해야 한다. 안전과 신뢰성이 중요한 철도시스템의 시험평가 분야는 사양에 따라 제작된 단위제품 및 시스템의 기본성능을 확인하고, 신뢰성과 안전성을 확인하여 상용화하는 측면에서 최종 확인하는 중요한 작업이다. 이러한 필요성에 의해, 본 연구진은 틸팅차량을 종합적으로 성능평가하기 위한 종합계측시스템 구축에 관한 연구를 수행하였다.

보조컨버터는 철도차량의 전체 성능을 좌우하는 매우 중요한 요소이다. 두 장치에 대한 다양한 성능을 평가하고 진단하기 위해 상시계측시스템을 구축하였다. 상시계측시스템을 통해 보조컨버터에 대한 계측 및 분석을 통한 시험평가와 동시에 완성차시험이나 본선시운전 시험시에 발생한 수 있는 고장원인을 찾아내고 해결하는데 많은 도움을 주고 있다. 본 논문에서는 상시계측시스템을 통해 보조컨버터에 대한 고장진단을 실시한 연구내용에 대하여 기술하였다.

고속철도 운행 및 급증하는 철도교통 수요에 대처하기 위해 기존선 속도향상이 요구됨에 따라 180km/h급 틸팅차량을 개발 중에 있다. 일반적으로 곡선부에서 승객들의 승차감을 위해 열차의 통과속도를 제한하지만 틸팅차량은 대차에 틸팅장치를 장착하여 차량의 곡선 통과속도를 향상시킬 수 있다. 곡선부에서 증가된 속도로 이 열차를 주행할 수 있도록 허용할 뿐만 아니라, 운전자의 실수, 고속주행으로 인한 탈선을 예방하기 위해 연속적으로 열차속도를 감시하는 것이 필요하다. 게다가, 기존선의 어떤 구간에서는 엄격한 틸팅의 승인이 있어야 하는 구간이 존재할지도 모른다. 틸팅열차가 열차간 충돌, 터널, 다리, 반대편의 열차와 충돌을 피해만 한다. 이러한 문제점의 해결은 TASS장치의 개발과 설치로 해결될 수 있다. 본 논문은 EMU 타입 틸팅열차에 적합한 TASS 장치의 적용방안을 제시한다.

Tilting trains are now an established feature of railway operations throughout the world. For intercity traffic, tilt provides operators with increasing speeds, and therefore enhanced competitiveness, on existing routes where insufficient traffic or a lack of funds precludes the construction of a dedicated new high-speed railway. This paper explains the reduction effects of journey time with the Korean tilting train. The Korean Tilting Train express (TTX) project has been carried out to develop alt the core technologies related to tilting train and infra-technology to provide high speed inter-city service with the speed of 180 km/h as well as maintenance-free technology for conventional railway system. In order to simulate we considered 5 conventional railway. As a results of simulation, we found out the tilting train has very high efficiency(reduction rate 20-30%).

Railroad business had repeated continuous development. Is developing old line improvement skill that technique aging of railroad and hangup of transport capacity decline are happened and minimum expense is spent. Developed skill and equipment are important and examination and by this are important. Therefore, examine skill and examination formality of equipment, examination item, examination kind etc.. developed serving speed elevation of old line in treatise.

Being controlled by a pole placement, levitation system should need many sensors such as measure air-gap, velocity, acceleration, and so on. However, these sensors have observational errors by changed temperature. This paper proposed a output compensated command tracking controller for reducing the error and reducing sensors. Simulation results will be provided to show the validity of the proposed scheme.

열차의 위치를 검지하는 방식으로 널리 사용되고 있는 방식은 궤도회로를 이용하는 방식으로 간단한 구성과 신뢰성이 높은 장점이 있다. 하지만 설치 및 유지보수에 많은 비용의 발생 및 고정폐색방식으로 인한 연속적인 열차의 위치검지가 불가능하다. 궤도회로를 이용한 열차의 위치검지는 지상장치를 통하여 지상 센터에서만 열차위치의 파악이 가능하므로 이러한 방식의 위치검지는 수동형의 열차위치검지라 할 수 있다. 이에 반해 능동형 열차위치검지는 차상에서 열차의 위치를 검지하여 전방 및 후방열차, 지상센터 간 통신을 통한 해당 열차의 위치정보를 교환하는 방식이며 연속적인 열차위치의 검지가 가능하다. 하지만 궤도회로와 같은 수준의 신뢰성을 가지는 장치구성이 필요하다. 본 논문에서는 신뢰성 향상을 위하여 여러가지 센서들을 통합한 능동형 열차위치검지장치의 구성방안과 운영시나리오를 제안하고, 장단점을 분석한다.

본 논문은 고속선에 사용 중인 UM71-C 궤도회로에 대한 전기적인 특성에 관한 시뮬레이션 실행결과를 나타낸다. 고속선 운행선상의 샘플개소를 선정하여 환경에 따른 선로정수를 구하고 전송라인의 특성임피던스와 전파정수를 반영시켜 레일전압과 전류에 대한 시뮬레이션을 수행하였으며, 차상검측시스템에서 측정되어진 검측데이터 파형과 비교하였다. 이러한 모델링 작업은 궤도회로 구성요소의 기능저하를 사전 예측하여 열차의 안전운행을 확보하기 위한 기초자료로 사용되어 질 수 있으며, 또한 차상검측시스템에서 얻어진 검측데이터와의 비교를 통해 유지보수에 활용 가능한 활용지침 및 분석기준을 작성하기 위해 필요하다.

The approach, for ensuring the quality and safety of a railway software can be considered with two points of views seeing from products, and from processes. The process point of view is to validate maturity of the organizations in accordance to the judging processes of organizations, which are specified by CMMI(Capability Maturity Model Integration) or SPICE(Software Process Improvement and Capability dEtermination : ISO/IEC15504). In this paper, we are trying to find approaches to estimate the maturity of manufacturer and assessment organization in the railway system.

In this paper, dynamic simulation results for magnetically-levitated vehicles are resented. The dynamic equation and models for a half-bogie system are derived. The system includes primary suspension system, magnet module, spring-damper system and cabin. Also, the dynamic characteristics for the derived models are analysed. Using the results, levitation control algorithm can be designed to meet the performance requirements.

통합항해시스템이라 함은 자동화된 선박의 운용에 관한 것으로, 다양한 항해 센서(GPS, Gyro, Speed Log, echo sounder)를 이용하여 선박의 항해에 필요한 각종 정보를 입수하여 최적의 항로를 설정해주고, 운항의 안정성과 효율을 극대화시키는 시스템을 지칭한다. 즉, 선박의 운항에 필요한 다수의 모듈들을 독립적으로 운용하는 것이 아니라 이를 통합된 형태로 운용하여 효율을 극대화시키는 시스템이 통합항해시스템이라 할 수 있다. 통합항해시스템은 다양한 항해 센서들과 항해 시스템으로 구성되며, 다양한 항해 데이터들은 항해 센서로부터 수신하여 처리하는 동작을 수행한다. 즉, 통합항해시스템은 다수의 센서들로부터 수신된 정보를 평가하고 잠재적 위험과 무결성 저하에 대해서는 적절한 경고를 제공하여야한다. 따라서, 항해센서 데이터의 유효성(Validity) 및 모호성(Plausibility) 검사와 무결성 감시(Integrity Monitoring)는 통합항해시스템의 필수적 기능이라 할 수 있다. 본 연구에서는 IEC 61924 규격에 의한 항해센서로부터 수신된 항해데이터가 정확하고 유효함을 가지는 지에 대한 가치평가의 척도와 독립적인 데이터 소스로부터 데이터를 비교하여 검증하는 무결성, 정확도 이내의 정보를 완전하고 명확한 방법으로 사용자에게 제공하는 무결성 감시의 방법을 제시하며, 항해센서들에 의해 취득되는 항해 데이터의 무결성 검사를 통한 유효성, 적용가능성, 무결성의 평가방법을 기술한다.

철도에 있어서 주행중인 열차와 지상간의 열차무선통신네트워크는 종래의 음성통화를 주축으로 하는 열차무선의 기능에 더하여, 차량상태 정보나 동영상 정보의 차량-지상간 양방향 전송을 비롯하여, 무선통신기반 열차제어시스템(CBTC : Communication Based Train Control System) 등에 확대 응용되면서 그 중요성은 점점 더 증가하고 있는 추세에 있다. 이에 따라, 향후 시스템의 발전에 따라 통화 채널의 증가, 데이터 통신 등을 가능하게 하는 새로운 시스템의 구축이 필요할 것으로 기대된다. 따라서 본 논문에서는 철도 연선에 있어서의 열차와 지상 무선통신기지 간의 효과적인 핸드오프기법에 대하여 검토를 수행하였다.

Maglev is a non-contact traffic system in which cars are supported by magnetic force instead of wheels. This is a ground-breaking traffic system providing superior environmental friendliness and cost efficiency due to the minimal noise and vibration offered by its non-contacting nature. We study the present specification and performance of the low speed urban maglev system in Korea and other countries. After set up the test line, to success the "Commercialization of Korean Urban Maglev System" project, we establish proper requirement of maglev system in Korean environment on base of "Daejeon National Science Museum Maglev Establish Project".

분산 형 전원 및 석탄 가스화와 연계한 복합 발전이 가능한 용융탄산염 연료전지(MCFC : Molten Carbonate Fuel Cell)는 천연가스, 석탄가스 등 다양한 연료를 사용할 수 있고, 공해요인이 적고, 높은 에너지 변환효율을 가지고 있어 전력사업 분야에 적용 가능성이 가장 큰 새로운 발전방식이다. 국내에서도 1993년부터 선도기술개발 사업의 하나로 시작하여 현재 250 kW급 발전시스템 개발 연구가 진행되고 있다. 250 kW개발 전 수행한 100 kW급 MCFC 발전 시스템 개발 연구에서는 6,000cm2 급 단위전지 90장으로 구성된 50 kW급 MCFC 스택 2기 로 구성된 100 kW MCFC 스택과 이를 운전 평가를 위한 시스템을 완성하였다. 2005년부터 스택운전에 필요한 시스템 내 단위기기들에 대한 시운전을 진행 한 후 장착된 100 kW MCFC 스택 운전에서는 시스템 단위 기기의 고장으로 전 부하운전을 실시하지 못했지만 상압 상태에서 AC 50 kW 전력을 계통과 연계 운전 시험을 진행하였다. 향후 100 kW MCFC 시스템 보완후 재 운전 시험을 진행할 예정이다. 한편 병행하여 진행되는 250 kW 열병합 발전 시스템 개발에서는 시스템 상세설계 및 신형 분리판을 이용한 새로운 형태의 스택을 개발 운전시험을 진행하고 있다. 여기에서는 MCFC 발전 시스템의 개요와 시스템의 운전을 위한 운전 모드 그리고 스택 운전 내용을 요약하여 소개하고자 한다.

The increase of exhaust gas which is caused by with the industry activity which follows in the Industrial Revolution of the human being has had an influence on the globe climate system so that causes the problem of the greenhouse effect. As a comprehensive countermeasures, it has been prompted to save energy, build a structure environmentally friendly and use renewable energy sources that are continually replenished by nature-the sun, the wind, the Earth's heat, and plants. In addition, new technologies that turn these fuels into usable forms of energy-most often electricity, but also heat, chemicals or mechanical power have been applied actively to the social infrastructure. Therefore, there should be methods to manage forms of renewable energy effectively and securely. This paper proposes the web-based monitoring system for the wind power system of these methods and introduces the real web-based monitoring system installed in Daegwallyeong.

This paper describes the development of software platform of embedded controller for Fuel Cell System. The fuel cell system is complex which needs an embedded controller to execute multiple tasks. The software organized by modualarization and layered architecture can perform complicated control algorithms. By development of the software platform with architectural software, the fuel cell system's embedded controller has a reusability and a scalability. And the developed software platform guarantees a execution of multiple tasks.

In this paper, we examined 10 domestic samples of three different model using thermal, humidity freeze, thermal-endurance and damp heat test under IEC61215 photovoltaic module environmental endurance test condition. Three was almost no changes on power generation. Insulation resistance capacity was much higher than judgement standard but, showed unstable results depending on environmental test items. On external appearance test, there were two models which showed bubble, humidity penetration, seal melted frame phenomenon. From this results, the degree of aging under the external environment is a main cause that shortens photovoltaic module life time. So it is considered that the efforts for finding optimum condition of manufacturing process should be needed.

This paper proposes the optimal design method based on NDZ analysis to secure the islanding defection ability and to maintain the stability and power quality when the grid is connected. A PSiM-based model and analysis of the system is presented, specialty aimed at improving the effectiveness of phase shift anti-islanding method with frequency feedback, which causes the inverter current to be generated slightly lower or higher in frequency than the frequency of the terminal voltage. The proposed method can cause frequency jump with leading and lagging phase of output current in two line cycles. As a result, the proposed algorithm is more sensitive and reliable than the conventional phase shift method. Experimental results, on a 3 kW inverter connected to 220 V, 60 Hz utility, are discussed.

In this paper, we analyzed the effect of EVA Sheet Gel Content depending on curing condition for photovoltaic module. Gel Content was measured by manufacturing Glass/EVA Sheet/Back Sheet scheme at several curing temperature and curing time. And the surface analysis of EVA Sheet depending on process condition could be observed using SEM(Scanning Electron Microscope). Through this experiment, we could confirm that there are differences on Gel Content of EVA Sheet and surface configuration depending on curing temperature and curing time. To find out the optical characteristic dependency on curing condition, Class/EVA Sheet/Glass scheme was fabricated. The optical transmittance of EVA Sheet at visible wavelength was enhanced 5% when compared to Glass/Glass scheme. And the transmittance of $130^{\circ}C$/4min, $110^{\circ}C$/4min, $160^{\circ}C$/6min process condition was higher at ultraviolet wavelength range. These curing conditions could be regarded as the best process for suppression the discoloration speed of EVA Sheet under UV light.

The key of this study is the technical development to maximize electric energy production through PV generation system. Under a conventional MPPT control method, both input voltage and input current coming out from PV array had to be feed backed. Then, the system has complex structure and may fail to track Maximum Power Point of PV array when weather conditions changed urgently. A PV output senseless MPPT control for PV generation system is possible to solve the mentioned above. The best advantage is that the current flowing into load is the only one considerable factor. In case of a huge photovoltaic generation system, it can be operated much more safely than a conventional system. In this paper, a novel PV output senseless MPPT control for the PV generation system was proposed and applied to the manufactured system and the experimental results were shown. Authors are sure that it is the most useful method to maximize power from photovoltaic system with only a feedback of load current.

As the grid-connected photovoltaic power conditioning systems (PVPCS) are installed in many residential areas, this has raised potential problems of network protection on electrical power system. One of the numerous problems is an Island phenomenon. There has been an argument that because the probability of islanding is extremely low it may be a non-issue in practice. However, there are three counter-arguments: First, the low probability of islanding is based on the assumption of 100% power matching between the PVPCS and the islanded local loads. In fact, an island can be easily formed even without 100% power matching (the power mismatch could be up to 30% if only traditional protections are used, e.g. under/over voltage/frequency). The 30% power-mismatch condition will drastically increase the islanding probability. Second, even with a larger power mismatch, the time for voltage or frequency to deviate sufficient to cause a trip, plus the time required to execute the trip (particularly if conventional switchgear is required to operate), can easily be greater than the typical re-close time on the distribution circuit. And, third, the low-probability argument is based on the study of PVPCS. Especially, if the output power of PVPCS equals to power consumption of local loads, it is very difficult for the PVPCS to sustain the voltage and frequency in an island. Unintentional islanding of PVPCS may result in power-quality issues, interference to grid-protection devices, equipment damage, and even personnel safety hazards. So the verification of anti-islanding performance is strongly needed. In this paper, the authors propose the improved RPV method through considering power quality and anti-islanding capacity of grid-connected three-phase PVPCS in IEEE Std 1547 ("Standard for Interconnecting Distributed Resources to Electric Power Systems"). And the simulation and experimental results are verified.

본 논문은 3[kW]급 연료전지와 연료전지의 저전압$[40{\sim}60[Vdc]$)을 승압(380vdc)하기 위한 풀-브리지 DC-DC 컨버터, 그리고 승압된 링크전압을 교류 상용전압(220[Vac], 60[Hz)으로 변환하기위한 단상 풀-브리지 인버터로 구성된 연료전지 발전용 전력변환시스템 중 연료전지 시스템용 DC-DC 컨버터를 제안하였다. 제안한 연료전지 시스템용 DC-DC 컨버터는 변압기 2차측에 배전류 정류회로를 삽입하여 기존의 고주파 변압기 보다 간단하면서 무게 및 부피를 줄였다. 그리고 위상 천이 PWM 제어로 출력 전압을 가변시켜 영전압 스위칭을 달성 함으로써 스위칭 손실을 줄였으며. 효율을 95%이상 달성 하였다.

청정하고 무한한 신재생에너지원에 대한 연구가 전 세계적으로 활발히 진행되고 있는 가운데, 태양광발전(Photovoltaic ; PV) 분야는 일본, 독일을 위시한 유럽, 그리고 미국을 중심으로 활발한 공급과 수요가 이루어지고 있다. 실제로 태양광발전시장을 분석한 결과, 2005년 태양전지의 생산은 전년대비 45%이상의 증가율을 나타내었고, 태양광발전시스템의 설치 부분에서 있어서도 전년대비 약 34%의 증가율을 나타내었다.

This paper presents performance monitoring results of large scale photovoltaic (PV) system supported by general dissemination & regional energy program in korea government polices for new and renewable energy resources. 80kW PV system and monitoring system is constructed and monitored PV system performance to observe the overall effect of environmental conditions on their operation characteristics. The PV system performance has been evaluated and analyzed for component perspective (PV array and power conditioning unit) and global perspective (system efficiency, capacity factor, and electrical power energy and power quality etc.) for six month monitoring periods.

Recently, the concern for environmental issue has been rising in the world such as global warming and breaking of ozone barrier by exhausting carbon dioxide(CO2) and Freon. In this situation, Photovoltaic(PV) and hydrogen energy system for utilizing clean and renewable energy was highlighted to contribute very much against the global warming prevention. Until now, authors have studied EMTDC model Development of Solar-powered Hydrogen production system and manufactured the 600W class actual PV-SPE system. Which was established in 2004 to produce highly pure hydrogen energized by PV power generation system. Sooner, authors will establish 100kW class PV-SPE system. Economically, this system produce large amount of hydrogen. In this paper, all data of 100kW class PV-SPE system will be simulated by using PSCAD/EMTDC.

Grid connected PV(Photovoltic) generation systems are becoming and actual and general. The power output of PV system is directly affected by the weather conditions. And when AC power supply is needed, power conversion by an inverter and a MPPT control are necessary. The PV power generation system can be treated to a harmonics source for the power distribution system. So, the PV system combined the function of active filter system can be useful applied in power distribution system. AF(Active Filters) intended for harmonic solutions are expending their functions from harmonic compensation of nonlinear loads into harmonic isolation between utilities and consumer. With the test analysis of the proposed control strategy of PV-AF system, the outcome of the test shows the stability and effectiveness of the proposed PV-AF system. The various capability of AF has been proved in previous research and usage. In this paper, authors present a DSP controlled PV-AF system for power conditioning in three-phase industrial or commercial power systems and verify it through experimental results.

RS-232, RS-485, LAN 등 다양한 네트워크를 통한 모니터링 기술은 통신 기술의 발달과 함께 급속도로 발전해 왔다. 신 재생에너지 분야 또한 다양한 모니터링 기술이 개발되고 선보이고 있다. 모니터링 기술들은 시스템의 정상운전여부, 발전량, 효율 등의 실시간 감시에 유용하게 활용되는 중요한 요소로서 원활한 동작과 시스템의 지속적이고 안정적인 운전을 필요로 한다. 특히, 동시에 여러 데이터를 받아 처리해야 하는 환경적 요소를 내포하고 있어서 Multi-Ch 데이터 처리가 매우 중요하다 할 수 있다. 본 논문에서는 LabVIEW를 이용하여 신재생에너지 시스템에 적합한 Multi-Ch 데이터 처리가 가능한 시스템을 설계 및 개발하고자 하였다.

The Photovoltaic(PV) generation system is a promising source of energy for the future. Since the need for renewable energy has been increased, the research of PV generation system has also been progressed. The main subject of this paper is about making the more useful real-time monitoring program to get and save the data from photovoltaic generation system of 30kW grid-connected. Therefore, it uses LabView for this real-time monitoring program.

본 논문은 신재생에너지 발전전원 중 단속적 특성이 강한 풍력발전 전원의 용량가치 평가방법에 관한 것이다. 풍력발전의 설비가치는 확률론적 접근방법과 용량률에 의한 결정론적 접근방법을 사용할 수 있으며 미국의 주요 산정방법을 살펴보고 국내 적용가능한 대안을 수립한다. 풍력발전의 설비가치를 실효성있게 산정하기 위해서는 관련자료의 확보가 우선되어야 하나 국내의 자료확보체계 및 그 기간이 짧은 관계로 용량률에 근거한 단순기법이 실효성이 있을 것으로 판단된다.

본 논문은 해외 신재생에너지 발전전력의 구입가격에 관한 제도 및 구입가격 결정 방법론을 통해 시사점을 파악하여 활용방안을 도출한다. 신재생에너지 발전전력은 기존 전원에 비해 발전원가 수준이 높은 상황에서 보급확산을 위해 유럽을 중심으로 다양한 신재생에너지 발전전력 구매정책을 수립하여 시행하고 있다. 국내에서는 발전차액지원제도를 통해 신재생에너지 발전전력을 높은 가격에 의무구매하고 있는 상황에서 해외 주요국의 제도현황과 접근방법을 파악하여 국내 발전차액지원제도의 수립에 활토록 한다.

This paper is aimed at presenting a computational model of a proton exchange membrane (PEM) fuel cell stack. The proposed simulation model is simple and at the same time includes all the important characteristics of a fuel cell stack. Close agreement between the simulation, manufacturer and experimental results confirm the validity and usefulness of the proposed FC model. Also, we propose the variable PI control method which has the best of follow efficiency than the PI control method. we confirm a reduced ripple and improved follow efficiencies when the system is applied the DC-DC converter, by simulation using PSIM.

The solar power system comprises a solar battery that directly converts light energy to electrical energy with a photovoltaic effect and a power converter system, that is, inverter that converts direct current power, which is generated from solar battery to common alternating current. In this paper, database was constituted through remote monitoring supervision measurement for the long-time positive operation of 3kW solar power system installed within the solar energy positive research complex of Chosun University. As a result of analyzing the reduction of the efficiency of solar battery and inverter that are compositional components of PV system through an analysis on the acquired data, the PV output was proven over 65% of the total output when insolation intensity exceeded 600W/m2 in 2005, and the array conversion efficiency dropped much more than rating; meanwhile, insolation intensity dropped below 600W/m2. Therefore, it has been demonstrated that approximately 35% of the entire amount of PV output operated under the condition that the inverter efficiency rate dropped rapidly by 60 to 70%.

Using the MATLAB/SIMULINK, this paper presents dynamic simulation model for 6MW wind power generation systems with the DFIG considering distribution systems and performs the dynamic analysis of wind power systems

The wind turbines of various designs have been manufactured and operated for many years. The design considering the wind circumstance is required for the high efficient wind turbine, because the efficiency and characteristics of the wind turbines depends on the designs and structure of it's system. In this paper, a analysis on the output characteristic of the wind turbine according to wind velocity was performed. The results of the analysis data is desired to be used on the high efficient blade design.

This paper a new method which applies a genetic algorithm for determining which sectionalizing switch to operate in order to solve the distribution system loss minimization re-configuration problem. In addition, the proposed method introduces a ultra efficient MPP tracking in a solar power generation system.

본 논문은 연료전지와 플라이윌 저장 시스템용을 결합한 복합전원으로 하는 연료전지 발전 시스템의 전력변환장치 연구에 관한 것이다. 이를 위한 전력변환장치는 연료전지로부터 저전압을 상승시키기 고조파 DC-DC 컨버터 이를 안정된 교류전원으로 변환하기 위한 DC-AC 인버터 및 플라이휠에 에너지 회생과 재생하기 위한 DC-AC 컨버터로 구성된다. 본 연구에서는 기존의 UPS 시스템은 AC 발전기 및 배터리를 백업 전원으로 사용하는데 맡은 유해 물질을 발생시키지만, 이 시스템을 사용하면 환경 오염, 높은 효율 및 대용량에 적합하다. 또한, 시뮬레이션을 통하여 연료전지 발전 시스템에 과부하시 안정하게 출력 성능을 가지도록 Fly-Wheel 시스템을 적용한 모의실험 결과를 제시한다.

This paper propose method of maximum power point tracking using boost converter for a connected single phase inverter. The maximum power point tracking control is based on generated circuit control MOSFET switch of two boost converter and single phase inverter uses predicted current control to control four IGBT's switch in full bridge. The predicted current control provide current with sinusoidal wave shape and inphase with voltage.

전력계통에 적용하기 위한 풍력발전시스템의 연계변압기 결선방법과 배전계통의 고장전류와의 관계를 알아보고 계통에서의 단상 고장전류 발생 시 변압기 결선 방식의 변화에 따른 simulation을 수행하고자 한다.

현 시대는 자원고갈 및 환경오염에 대한 대책으로 신재생 에너지시스템의 실용화 보급이 활성화하는 추세이며 이러한 일한으로 태양광 발전을 비롯한 분산형 전원은 계통될 경우 여러 가지 문제를 일으킬 수 있고 그 중 단독운전으로 계통보호측면에서 반드시 검출되어, 이 단독운전 태양광 발전시스템은 직류전동기와의 연계운전 시뮬레이션 하여 운전에 따른 시스템 주변장치의 성능개선 및 연계기술 개발을 도모한다.

The wind turbine system, one of the distributed resource, has a large effect on the distribution system. because windfarm is located in the end part of the distribution system, the hilly section and the shore, which is easy to obtain the wind energy, it is difficult to manage the voltage and the power quality. Therefore this paper deals with the measurement and assessment of power quality characteristic of wind turbines with IEC 61400-21.

In this paper, I try to measure the electrical characteristics of PV cell for lanterns with solar simulator and simulated with PC1D software. I keep my eye on the characteristics variation of PV cell as a temperature change. Therefore, I try to increase a temperature of controlled block from $10^{\circ}C$ to $50^{\circ}C$ while measuring the PV cell. As a result, A variation caused by voltage have an effect on the efficacy of PV cell. Hence, it is an important variable when a designer plan to make a solar cell for lanterns.

In this paper, I try to measure characteristic transmission-reflection by environmental change or solar cell. I keep my eye on the characteristics variation of solar cell as environmental change. As a result, A variation caused by voltage by an effect on the efficiency of solar PV cell. Hence, it is an important variable when a designer plan to make a solar cell.

Recently, utility network is getting more and more complicated and huge. In addition to, demands of power conversion devices which have non-linear switching devices are getting more and more increased. Consequently, according to the non-linear power semiconductor devices, current harmonics are unavoidable. Those current harmonics flow back to utility network and become one of the reasons which make the voltage distortion. On the other hands, voltage sag from sudden increasing loads is also one of the terrible problems inside of utility network. In order to compensate the current harmonics and voltage sag problem, AF(Active Filter) systems could be a good solution method and SMES(Superconducting Magnetic Energy Storage) system is a very good promising source due to the high response time of charge and discharge. Therefore, the combined system of AF and SMES is a wonderful device to compensate both harmonics current and voltage sag. However, unfortunately SMES needs a superconducting magnetic coil. Because of the introduction of superconducting magnetic coil, quench problem caused by unexpected reasons is always existed. In case of discharge operation, quench is a significantly harmful factor according as it decreases the energy capacity of SMES. Therefore, this paper presents a decision method of the specification of the AF-SMES system considering internal fault condition. Especially, authors analyzed the change of the original energy capacity of SMES regarding to the size of resistance caused by quench of superconducting magnetic coil. Finally, based on this simulation, authors manufactured actual Active Filter System using DSP.

In this paper an integrated model of PV-AF (Photovoltaic-Active Filter) and PV-SPE (Photovoltaic Solid Polymer Electrolyte) system using PSCAD/EMTDC were explained in detail. The main concept of PV-AF system starts from the "harmonics". In order to deliver power to utility, PV system essentially needs a converter system. Here PV-AF system adds the function of active filter to the converter system installed in PV system, which was introduced already in several papers. PV-SPE system has been studied as a replacement of existing hydrogen production technology that emits large amount of carbon dioxide into atmosphere. Until now, these two systems, PV-AF and PV-SPE, have been considered separately. However, in this paper, characteristics and advantages of combined system are discussed in detail.

Recently, a fuel cell with low voltage and high current output characteristics is remarkable for new generation system. It needs both a DC-DC step-up converter and DC-AC inverter to be used in fuel cell generation system. Therefor, this paper, consists of an isolated DC-DC converter to boost the fuel cell voltage 380[VDC] and a PWM inverter with LC filter to convent the DC voltage to single-phase 220[VAC]. Expressly, a tapped inductor filter with freewheeling diode is newly implemented in the output filter of the proposed high frequency isolated ZVZCS PWM DC-DC converter to suppress circulating current under the wide output voltage regulation range, thus to eliminate the switching and transformer turn-on/off over-short voltage or transient phenomena. Besides the efficiency of 93-97[%] is obtained over the wide output voltage regulation ranges and load variations.

This paper presents a single phase high power factor PWM boost rectifier featuring soft commutat -ion of the active switches at zero current. It incorporates the most desirable properties of conventional PWM and soft switching resonant techniques. The input current shaping is achieved with average current mode control and continuous inductor current mode. This new PWM converter provides zero current turn on and turn off of the active switches, and it is suitable for high power applications employing IGBT's. The principle of operation, the theoretical analysis, a design example, and experi -mental results from a laboratory prototype rated at 1.6[kW] with 400[Vdc] output voltage are presented. The measured efficiency and the power factor were 96.2[%] and 0.99[%], respectively, with an input current THD equal to 3.94[%], for an input voltage with THD equal to 3.8[%], at rated load.

본 논문에서는 5 kWh급 초전도 플라이휠 에너지 저장장치(Superconductor Flywheel Energy Storage System : SFES)를 제작하고 시험운전을 통하여 회전 테스트를 수행하였다. 본 연구에서 사용된 초전도 베어링은 저널형 베어링으로써 액체 질소를 순환시켜 초전도체를 냉각시키고 휠을 부양시켜서 전동발전기를 통하여 회전시키게 된다. 액체 질소를 순환하였을 경우 초전도 베어링의 냉각특성을 고찰하였고, 전동 발전기를 이용하여 2000[rpm]까지의 회전 테스트가 수행 되었으며, 전동발전기의 동작 특성 및 회전시 휠의 궤적과 축진동 특성을 테스트 하였다.

전력계통의 과도현상 분석용으로 개발된 수치계산 프로그램인 EMTP(Electromagnetic Transient Program)를 사용하여 건물내에 낙뢰에 의한 뇌서지가 침입했을 때 건물 전체에 surge current가 어떻게 확산되어 가는지를 분석해 본다. 이러한 현상을 분석하기 위해서 건물의 등가회로를 $\pi$-회로로 구현하고 ANSI 규격에 맞는 뇌서지를 건물에 유입시켜서 그에 따른 건물 내부의 current 분포를 알아본다. 그리고, 건물 체적을 변화시켜가면서 뇌 서지가 건물 내부의 전기기기에 미치는 영향을 해석해 본다.

본 연구의 목적은 Pspice를 이용하여 SI Thyristor의 구조적인 특징과 스위칭 동작을 설명하면서도 비교적 간략화된 등가 모델을 개발하는 것에 있다. 이러한 목표로 등가모델은 SI Thyristor의 구조적 형태에 기반을 두어 BJT 소자를 이용한다. 또 게이트 구조와 스위칭 매커니즘을 고려한 MOSFET, Steady state Turn on 상태에서 dominant 모델인 PIN Diode로 구성되어 있다. 개발된 등가모델을 스너버회로와 함께 스위칭 과도응답을 시뮬레이션하였으며 그 결과는 실제 실험결과와 비교하여 검증하였다. 비교적 간단하게 고안된 회로를 통해 Turn On/Off 동작에서 스위칭 특성을 예측할 수 있으므로 펄스파워용 스위치로서 SI Thyristor의 시동특성을 해석하는 데 본 등가모델을 활용할 수 있을 것으로 전망한다.

태양전지는 일사량에 따라 그 출력특성이 변화하기 때문에 태양전지로 부터 최대출력을 얻기 위해서는 컨버터에 의한 최대 전력점 추종제어가 필요하다. 본 연구에서는 태양광 발전시스템의 최대전력추종을 위해 퍼지 이론을 도입한 퍼지제어기를 설계하였다. 그리고 퍼지제어기의 디지털 설계를 위해 태양광 발전시스템의 각 부분을 구성하고, 마이크로프로세서와 FPGA의 두가지 방식으로 제어기를 구현하였다. 또한 구현된 두 가지 방식의 퍼지제어기에 대해 실험을 통하여 비교분석 하였다.

본 논문에서는 Half Bridge Series Resonant Inverter를 이용한 유도가열 시스템 설계를 하고 제작하여 구현하였다. 이러한 유도가열 시스템의 제작을 위해서는 공진탱크와 매칭 트랜스포머의 설계가 필수적이다. 따라서 이런 설계를 위해 PSpice 를 이용하여 공진탱크의 입력 임피던스 Bode Plot 을 그려 분석하고 이를 바탕으로 탱크회로를 설계 하였다. 매핑 트랜스포머의 설계는 출력 Power 와 1,2 차 회로 조건에 의해 설계 되어졌다. 이렇게 설계한 유도가열 시스템을 Pspice 를 이용해서 Simulation 함으로써 주파수에따른 출력 Power 의 변화를 볼수 있었으며, 유도가열 시스템을 실제 제작하여 구현함으로써 확인하였다.

이 논문에서는 자기에너지 회생 스위치(MERS)를 이용한 3상 유도전동기의 역률개선을 목표로 한다. 기존의 MERS는 단상의 유도성 부하에 대해서는 간단한 제어 방법을 통하여 역률을 개선시키는 효과가 있는 스위치로 알려져 있다. 이러한 스위치의 기능을 응용하여 논문에서는 실제 전철 등의 구동시스템에서 사용하는 3상 유도전동기 부하를 가진 시스템에 MERS를 적용시켰을 때 어떠한 이점들이 발생 하는지를 제안한다. 시뮬레이션을 위해 실제로 사용되는 3상 유도전동기와 이를 구동시키기 위한 컨버터와 인버터가 포함된 모터 구동 회로를 직접 구성하였다.

This paper presents the results of a grid-connected photovoltaic(PV) system modeling that contain incremental conductance MPPT(Maximum Power Point Tracking) controller by PSCAD/EMTDC simulator and investigates the influence that can occur in the grid-connected PV system from aspect of power quality, i.e. voltage drop, total harmonic distortion(THD) and total demand distortion(TDD). The measured data the PV array modeling of PSCAD/EMTDC in Cheongwadae, Seoul, Korea is used in the paper.

This study is for implementation of PC based Motor fault diagnosis system. By using harmonics and current signals of the motor, this system diagnoses the motor condition by accumulated harmonic contribution rate. In this proposed system that was composed of 5 parts. A sensor, connection box, evaluation board, device server, and main computer are those. There were two types of sensor, one was harmonic sensor the other was current sensors. The signal was acquired by sensor, and transferred to evaluation board. Second one is connection box. Because the output type of sensor and input type of evaluation board is different, connection box was necessary. Third one was evaluation board. The signal from the sensor was converted to digital signal in evaluation board. And this signal was transferred to device server. Fourth one was device server. Device server transferred the data from evaluation board to main computer. And the last one was other parts controlled by main computer in main computer, there were communication and diagnosis algorithms. The result was derived by main computer. In the result, there were 12 categories and 5 levels of motor conditions. The proposed system had some advantages comparing with stand alone type commercial motor fault diagnosis system. The first, by using remote access it was easier to get the conditions of motor. The second, there was no need to handle the sensors when users measured the motor signals. By this property, no one was necessary at motor location site. The third, this system was less restricted by times and places than commercial stand alone type diagnosis system. Therefore users can operate this system only using the main computer. Once the sensors are installed at the motor, users doesn't need to move to check up the condition of motors. Moreover, if there is ethernet hub, many motors can be not only diagnosed at once but also decreased its cost.

본 논문은 역률개선 효과가 있는 MERS(Magnetic Enery recovery switch)를 사용하여 에너지 효율에서의 결과를 입증하고자 한다. 전원과 유도성부하에 직렬 연결된 MERS는 Full Bridge와 비슷한 구성으로 전력용 MOSFET(or IGBT) SWITCH 4개와 전해 DC콘덴서 1개로 구성되어진다. MERS의 콘덴서는 부하와 콘덴서의 리액턴스, $X_C<X_L$을 만족하는 콘덴서의 용량을 선택하고 콘덴서에 충전된 전압에 의해 부하의 유도계수를 보상하여 역률을 1로 추종하며 개선된다. 이때 스위치는 전원 전압에 대해 zero-voltage switching 과 zero-current switching을 하게 된다. 만약 부하가 변하더라도 $X_C<X_L$을 만족한다면 자동적으로 역률은 1에 맞추어지게 된다.

Reliable frequency estimation is important for active power control, load shedding and generator protection. Thereby, frequency estimation is researched and some algorithms is proposed. This paper analyzed strength and weakness of each algorithms through comparative analysis of frequency estimation. Used algorithms are Zero Crossing detection, Discrete Fourier Transformation, Least Error Squares.

In this paper, we designed high performance, high quality and high density switch mode power supply for precision electronics, and communication equipments. For this, we used two parallel DC-DC converters, which have opposite phases, to support proper high performance and high quality power. To reduce switching losses and make high switching frequency, active-clamp and ZVS technique were employed in each converter.

When the coil with alternating current approaches to the conductor the eddy current flows in conductor. Eddy current is concentrated on the conductor surface and decrescent because of skin effet.. In this paper investigated eddy current characteristic that is happened in conductor. Analyzed characteristic using electromagnetic field finite element analysis program that is commercialized to analyze value of eddy current and penetration depth. Analyzed creation value of eddy current and penetration depth in conductor that change operation frequency and the material of conductor, coil outside diameter, inside diameter, position, type of conductor from analyzed eddy current characteristic. The results. using distribution of eddy current and penetration depth data is that will help to forecast ECT(Eddy Current Testing), Eddy current application and use field, eddy current loss.

본 논문에서는 1kVA급 비선형 부하에서 발생한 고조파 전류의 저감을 위한 시스템을 설계 및 제작하였다. 제안된 시스템은 비선형 부하의 차수별($3{\sim}9$차) 고조파 발생량을 검출한 후 설정된 기준치를 넘어서는 고조파들을 저감할 수 있도록 해당하는 고조파의 수동 필터만 스위치를 이용하여 연결하는 구조를 가진다. 스위칭을 위한 제어기는 아날로그 소자만으로 구성되어 있다. 제안된 방법은 기존 수동 필터의 다양한 비선형 부하에 적용되지 못하는 단점을 보완하는 동시에 능동 필터보다 단순하며 저가로 구현할 수 있다. 형광등 부하와 다이오드 정류 부하에 대한 실험을 통해 제안된 시스템의 성능과 타당성을 입증하였다.

기존의 Gap switch를 이용한 Marx generator는 트리거-펄스 발생회로가 따로 필요하여 복잡한 구조를 가질 뿐만 아니라, 스위치의 짧은 수명과 스위치 내부의 스파크전류의 Jitter 현상, 그리고 순차적인 스위치 turn-on과 스위치 내외부의 인덕턴스로 인한 전압 상승시간의 지연 등의 단점을 가지고 있다. 본 논문에서는 이러한 단점들을 해결하기 위해 기존의 Gap switch대신 전력용 반도체 소자인 IGBT(Insulated Gate Bipolar Transistors) 스위치를 이용한 Marx generator를 제안하고, 제안된 회로의 동작을 구현하기 위해 전력계통용 전자기과도현상 해석프로그램인 EMTP(Electromagnetic Transient Program)를 사용하여 시뮬레이션 하여 IGBT스위치가 이상적인 동작을 할 때 얻어지는 이 점을 알아보기로 한다.

In this paper, PZT(20/80) thick films were fabricated by the screen-printing method. And the PZT(80/20) coating solution was synthesized by the sol-gel method. PZT(20/80) thick films were screen-printed on the alumina substrates. PZT(80/20) thin film was spin-coated on the PZT(20/80) thick films to obtain densification. And the structural and electrical properties of PZT thick films were investigated with variation of sintering temperature. The PZT specimen sintered at $650^{\circ}C$ showed good relative dielectric constant of 219 and dielectric loss of 2.45%. Also the remanent polarization and the coercive field were $16.48{\mu}C/cm^2$ and 35.48kV/cm, respectively.

Ferroelectric PZT (70/30) thick films were fabricated by the screen printing method. And the PZT (30/70) precusor solution were infiltrated by the spin-coating method on the PZT thick films to obtain a densification. All PZT thick films were sintered at $1050^{\circ}C$ for 10 min. Structural properties, such as crystalline structure, microstructures and compositional ratio, of PZT thick films were investigated with the variation of the number of sol coatings using XRD, SEM and EDS, respectively. All PZT thick films exhibited a perovskite polycrystalline structure without a pyrochloer phase. The thickness of PZT thick films, 4-times screen-printed, was approximately $60{\mu}m$. And the densification of the PZT thick films increased with increasing the number of sol coatings.

전력계통 수요예측은 주로 과거의 부하실적을 바탕으로 미래의 수요를 예측한다. 그러나 전력수요는 사회, 기상, 환경 등 다양한 분야의 영향을 받으므로, 예측의 정확성을 향상시키기 위해서는 전력수요에 영향을 미치는 요인에 대한 분석이 선행되어야 할 것이다. 본 논문은 전력총수요와 기상 상태와의 상관관계를 분석함으로써 기상이 전력총수요에 미치는 영향에 대하여 고찰한다. 기상 상태를 태풍, 장마 등 형태에 따라 분류하고 각각의 기상 형태가 전력총수요에 미치는 상관관계를 분석한다. 분석된 상관관계는 전력계통 수요특성에 관한 기본 자료로 활용될 수 있을 것이며, 기존 수요예측의 정확성 향상에 기여할 수 있을 것이다.

풍력발전은 친환경적인 에너지를 사용함에도 불구하고 그 에너지의 불안정성 때문에 실용화가 어렵다. 이를 극복하기 위해 효과적인 에너지 보상시스템이 필요하다. 본 논문에서는 유도기를 모티브로 해서 플라이휠을 등가 모델링 한다. 그 후 PSIM을 이용하여 풍력발전기의 지락사고를 설정하고, 플라이휠의 보상 유무에 따른 부하의 과도현상을 살펴 보고자 한다. 시뮬레이션 결과로부터 안정된 전력보상시스템의 구현할 수 있었지만, 한편으로는 고조파의 영향이 관찰되었다.

화석연료의 대체 에너지원 발굴 전 세계적으로 환경에 관한 경각심이 고조 그리고 개발도상국에서의 인구 증가에 따른 에너지 수요의 증대는 장기적으로 환경친화적이고 에너지원이 무한정한 태양광발전에 관심을 불러일으키고 있다. 최근 5년간 전 세계 태양광 생산은 매년 평균 40%씩 증가하였고 여기에는 태양전지 재료 및 공정기술의 발전과 함께 각국의 시장 활성화 정책이 큰 기여를 하였다. 이러한 추세에 따라 태양전지 효율 향상을 위한 새로운 개념의 도입 및 개발은 물론 태양전지 재료의 사용과 소비에 대한 새로운 기술개발과 태양전지의 설계 및 생산기술에 혁신적인 발전이 요구되고 있다. 현재 결정질 실리콘을 주 소재로 한 태양전지 생산은 매년 40%씩 증가하고 있고, 그 성장속도는 지속적으로 빨라지고 있다. 에너지 산업에서 새로운 에너지원이 시장을 장악하는 큰 변화가 있을 때 소요되는 기간을 감안할 때 태양광발전이 기존에너지 시장의 상당부분을 대체하기까지에는 앞으로도 20-30년 지속적으로, 나아가서는 보다 공격적인 성장속도가 필요할 것이다. 이러한 성장속도는 새로운 기술의 도입이 지속적으로 이루어질 때 달성이 가능하고 또한, 새로운 기술의 도입은 튼튼한 기초 연구가 그 바탕을 이루고 있을 때 가능할 것이다.

This paper aims to analyze the overvoltage in underground distribution systems when lightning surge strikes to overhead line. The model is established by EMTP/ATPDraw for actual distribution systems. Simulation is carried out considering variation of parameters such as length and lightning current.

전력 계통에서 과전류가 발생하게 되면 이것을 차단하기 위해 차단기가 동작한다. 차단기가 동작하게 되면 기계적으로 전기의 흐름을 단절시키므로 아크 현상이 발생한다. 이때 차단기의 차단 절차를 이해하기 위해서는 아크 현상의 모델링이 필요하다. 특히 포스트 아크 현상에 관한 정밀한 모델링이 이루어질 경우 차단기에서의 소호 특성을 파악하기 용이하다. 우리는 이 논문에서 전력 계통의 과도현상 분석 수치해석 프로그램인 EMTP(Electro-Magnetic Transient Program)를 이용하여 아크 현상에서 발견되는 포스트 아크 전류(Post-Arc Current) 및 TRV(Transient Recovery Voltage)를 반영하는 아크 모델을 설계하였다.

전기에너지는 저장성이 없기 때문에 부하의 불규칙적인 변화에 대한 실시간 대처가 어렵다. 그 중 전력계통의 대규모 공급지장에 대비하여 안정적인 공급을 위해서 예비력은 중요한 요소이다. 예비력이 필요 없다면 경쟁적 입찰을 통해 최적의 가격선정을 할 수 있겠지만 예비력은 계통의 안정적 운영을 위해 반드시 필요하다. 예비력을 운영함으로써 경제적 손실이 발생하는데 이를 최소화하기 위한 일환으로 예비력 운영에 대한 적절한 가격결정이 필요하다. 본 논문에서는 예비력시장을 운영함으로써 발생하는 기회비용을 고려하여 에너지와 예비력 가격 설정방법을 제시하였다.

High temperature superconducting(HTS) power cable is expected to be used for power transmission lines supplying electric power for densely populated cities in the near future. Commercializing of HTS power cable is coming. Simulation is required for safety before install of HTS power cable, a fabrication model used at the power system simulation. In this paper, we shows a single line-to ground fault analysis in the grid system which has a 100m length HTS power cable. The authors developed a single line-to-ground fault current calculation method which is considering the shield layer of HTS power cable. In the calculation, the T type equivalent circuit is used to derive the mutual inductance of the HTS power cable.

Electro-magnetic launcher(EML)는 전자기력을 이용하여 발사체를 추진시키는 장치이다. EML은 크게 레일건의 형태와 코일건의 형태로 구분되며, 본 논문에서는 코일건의 형태로 설계, 제작하였다. 코일건의 형태인 EML은 솔레노이드에 여자되는 전류에 의해서 발사체에 흡인력이 발생하여 추진, 가속되므로 솔레노이드의 최적형태를 설계하고, 이를 바탕으로 제작하여 EML의 스위칭 시간에 따른 속도를 측정하여, 여자전류의 스위칭 시간에 따른 동작특성을 해석, 실험하여 분석하였다.

자기누설탐상법은 비파괴검사 방법의 하나로 대상물체를 외부에서 착자시켜 결함이 발생할 경우에 결함부위에서 자기누설이 발생하도록 하여, 누설된 자기장을 측정하여 결함의 유무와 크기 등을 판정하는 시스템이다. 본 논문에서는 MFL 방식의 범용 NDT 검사기의 개발을 위해 영구자석을 이용하여 소형 비파괴 검사기를 설계하고, 3차원 유한요소법을 이용하여 해석하고 실제 데이터를 측정하여 그 결과를 비교 분석하였다.

Multi-stacked HTS tapes are needed to conduct large current in the power application of superconducting machine. This paper deals with the transport current loss of multi-stacked YBCO coated conductor. YBCO coated conductor that was used in this experiment has two Cu layers above and below of YBCO layer for stabilization. Transport losses of four different stacks, single, 2 stack, 3 stack and 4 stack, were measured. Measured results were compared analytic equation suggested by Norris.

Chemical mechanical polishing (CMP) technology has been widely used for global planarization of multi-level interconnection for ULSI applications. However, the cost of ownership and cost of consumables are relatively high because of expensive slurry. In this paper, we studied the mixed abrasive slurry (MAS). In order to save the costs of slurry, the original silica slurry was diluted by do-ionized water (DIW). And then, $ZrO_2,CeO_2$, and $MnO_2$ abrasives were added in the diluted slurry in order to promote the mechanical force of diluted slurry. We have also investigate the possibility of mixed abrasive slurry for the oxide CMP application.

We investigated the effects of oxidizer additive on the performance of Cu-CMP process using commonly used tungsten slurry. According to the CMP removal rates and particle size distribution, and the micro-structures of surface layer as a function of oxidizer contents were greatly influenced by the slurry chemical composition of oxidizers. The difference in removal rate and roughness of copper surface are believed to cause by modification in the mechanical behavior of $Al_2O_3$ abrasive particles in CMP slurry.

CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi-level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40%. So, we focused how to reduce the consumption of raw slurry. In this paper, $ZrO_2$, $CeO_2$, and $MnO_2$ abrasives were added de-ionized water (DIW) and pH control as a function of KOH contents. We have investigate the possibility of new abrasive for the oxide CMP application.

In recent, it became necessary to develop the technology about electrodeless fluorescent lamp according to demand of the electrodeless fluorescent lamp system that used higher efficiency and advantage of long lifetime. Inductively coupled plasma is commonly used for electrodeless lamp due to its ease of plasma generation. An electric power efficiency of electrodeless fluorescent lamp has big relative property of gas in lamp, gas pressure, lamp formation, ingredients of magnetic substance and shape and action frequency etc. We used magnetic substance that open self-examination material of electrodeless fluorescent lamp antenna. Ferrite that is used in this experiment was Mn-Zn type. We have examined temperature and flux characteristic by frequency. Considering using frequency 2.65[MHz], Frequency was changed from 2.05[MHz] to 3.05[MHz] to recognize flux and temperature change of lamp. I used LMS(Lighting Measurement System) to measure flux and IR Camera to measure temperature of lamp.

As developing the information society, Lighting Emitted diode(LED) which is light source for illumination of next generation is attracted public attention. LED have many problem as narrow light view angle, high price, drift phenomenon of color coordinate, high heating problem for lower power, lower weight and small size. So, many researches have continued in a illumination as LED module type. in this problem, heating problem is very important and difficult and that is caused in decreasing phenomenon of brightness and drift phenomenon of color coordinate. so the problem of heating is urgent question for illumination of LED. In this paper, structural design of PCB changed as two type for solving the heating problem. also the properties of heating is analysed and optical properties is measured with heating image camera and spectrometer according to change in this design.

본 연구에서는 그래픽 언어기반 소프트웨어인 LabVIEW와 Real-time Module 및 FPGA 모듈을 포함한 산업용 컴퓨터를 이용하여 BLDC 속도제어를 하려고 한다. 이 프로그램은 GUI기반으로 수집, 계측, 제어부분에 탁월한 성능을 가지고 있는 그래픽 언어이다. BLDC 속도제어를 하기 위해서 BD80-220N100의 BLDC를 사용하였으며, 드라이버를 연결하여 BLDC 속도제어 GUI 프로그램을 구현하였다. BLDC 속도제어를 하기 위해서는 먼저 속도 측정하여 모터의 속도에 대한 안정도를 판별하고 사용자가 원하는 응답에 안정하면서 빠르게 도달할 수 있도록 PI 속도제어를 하였다. 이를 바탕으로 그래픽 언어에 대한 이해 및 프로그램 코딩 습득을 하여 BLDC 모터 속도제어에 전반적인 가치를 두려고 한다. 본 연구를 통하여 하드웨어를 구성하거나 일반적으로 쓰는 텍스트 언어를 사용할 경우와 비교하여 수월하게 알고리즘을 변경시키며 유연성 있는 프로그램을 구현하였다.

병렬선재를 사용하여 권선을 제작할 경우 구성하는 초전도 선재의 임피던스의 차이에 의하여 통전전류 불균형이 발생하게 된다. 본 논문에서는 BSCCO 선재를 사용하여 제작된 병렬선재에서 전류불균형 분포에 따른 교류손실을 측정하였다. 4 가닥 병렬선재의 경우 전류 불균형이 발생한 선재에서의 교류손실이 전류 불균형이 일어나지 않을 때보다 2배 이상 증가함을 확인하였다.

전동차 운행시스템은 속도를 지령하는 NOTCH의 상태를 전압으로 인식하여 주파수로 변환한 후 주파수 변환신호를 출력하는 아날로그 및 디지털 인코더와 인코더의 주파수 변환신호를 입력받아 카운트하여 노치의 상태를 데이터버스(DATA BUS)에 실어 중앙처리장치(CPU)에 데이터를 출력하는 특징을 갖는다. 이런한 전동차 신호전달시스템 분석을 본 연구에서 하고자 한다.

기존의 89S51의 Flash Memory에 데이터를 저장하기 위해서 패러럴 포트를 사용하였다. 하지만 패러럴 포트를 이용한 방법은 많은 단점을 갖고 있는데, 그 중에 하나의 포트에 하나의 디바이스밖에 접속 할 수 없기 때문에 여러 디바이스를 접속하기 위해서는 포트 수를 증가시켜야 한다는 문제점이 있다. PC는 패러럴 포트를 $1{\sim}2$개 정도만 갖고 있어서 확장을 하기가 여의치 않다. 이에 따라 패러럴 포트의 단점을 보완하고자 한다. 이러한 문제를 해결하고 보완 할 수 있는 USB 통신을 이용해 Micro-Controller인 89S51에 내장된 Flash Memory에 데이터를 저장 하려고 한다.

차세대 무선통신 'ZigBee'는 표준인준으로 상용화가 임박하였으며, 저전력을 장점으로 홈 네트워크에 가장 적합한 것으로 평가되고 있다. 그래서 우리는 이러한 ZigBee 통신과 현재 가장 보편화 되어있는 휴대용 단말기인 휴대폰을 이용하여 원거리에서 가정을 감시 및 제어 할 수 있는 시스템을 구축하였다.

본 연구에서는 2-port probe를 설계, 제작하고, 이를 이용하여 유전율과 투자율을 동시에 측정해내는 기법을 연구하였다. 기존에는 유전율 측정을 위해 끝이 open되어 있는 1-port probe를 주로 이용하였지만 이는 유전율만이 측정이 가능하고 주파수 대역에 한계가 있었다. 2-port probe는 유전율과 투자율이 동시에 측정이 가능하며 주파수의 한계를 극복하였다. 2-port probe를 등가화 하여 이를 수식적으로 해석했을 경우 수많은 변수들이 발생되는데 이것을 여러 수치기법들을 이용하여 정리한 후, 유전율을 알고 있는 용액들을 이용하여 보정하였다. 또한 2-port probe에 약간의 길이 변화를 주어 주파수대역의 변화를 실험을 통해 비교 분석하였다.