SRM(Switched Reluctance Motor) uses reluctance torque by pulse excitation control. SRM drives are much studied in electrical vehicles and industrial application due to the simple, robust mechanical structure and high speed characteristics. For the high performance control of SRM, it is necessary to synchronize the stator phase excitation with the rotor position. This paper proposes a new encoder for high performance excitation control of SRM. The proposed encoder has complex structures of incremental and absolute encoder. An each phase inductance profile can be synchronized with 4-bit absolute position signal and incremental pulses are used for speed detection. Low cost and simple manufacturing of SRM encoder is possible.

The low cost, ruggedness, and reliability of switched reluctance motor(SRM) drive makes them potentially suitable for many industrial applications. But the generation of a high-level torque ripple and the acoustic noise restricts the practical application range. This paper analyzes the torque characteristic of SRM according to rotor pole arc and the effect of turn-on and turn-off angles to reduce the torque ripple. The simulation result shows the different torque characteristic of each cases.

This paper proposes the electric stimulus tactile apparatus system(TESTAS) loaded on the hap-tic interface using ultrasonic motors(USMs). To touch the virtual object like wall in graphic, the 6 DOF haptic interface provides force feedback to users as if it is real. But the case of sharp virtual object like a puncture, it could not provided the sense of pain, but only the reaction-force. After the TESTAS had been loaded on this haptic interface. it could Provide not only the force but also the pain to users. To estimate the capability of TESTAS, we did experiments of three cases, one was very sharp, another was dull, the other is continuative contact.

In this paper, the vibration characteristics of a 2-phase Hybrid type Linear Stepping Motor(HLSM) are analyzed using the ACSL. A magnetic equivalent circuit is based on the structure of the HLSM, and then the electric equivalent circuit of the HLSM is derived by solving equations for the magnetic equivalent circuit. A normal force is calculated using FEM(Flux2D). And the vibration characteristics of the HLSM are simulated by the ACSL with the voltage equations, the thrust equation, the normal force equation and the kinetic equation.

This paper describes the method of vibration supprssion on a control algorithm using Neuro-Fuzzy Theory in Linear Pulse Motor (LPM). The total thrust force Is distorted by magnetic and coil flux, and we classify the harmonic parts of it. A modulated current from harmonic components of static thrust characteristics of LPM compensates with reference current to total thrust force. Low vibration is obtatained by the method of current compensation using ANFIS.

This paper presents the characteristics of current harmonics and torque ripple of Brushless DC motor, which is developed the fan blower of vehicles, according to input voltage waveform. To investigate the torque ripple and the phase current harmonics, these characteristics is analysed and compared the experimental results. In the process of analysis, FEM is introduced and computed a transient state torque of BLDC with a sinusoidal and a PWM wave voltage.

The BLDCM (Brushless DC Motor) characterized by linear torque to current, and speed to voltage has low acoustic noise, and fast dynamic response. Moreover, it has high power density with high proportion of torque to inertia in spite of small size drive. But, it produce torque ripple due to the motor inductance components in stator windings and back-EMF, when armature current is commutated. Therefore, it is difficult to apply the BLDCM to a precision servo drive system. In this paper is proposed to a new current control algorithm with using fourier series coefficients can minimize torque ripple due to the phase current commutation of BLDCM. Simulation and Experimental results prove the effectiveness the proposed algorithm through comparison with the conventional used unipolar PWM method.

Advantages of switched reluctance motor(SRM) drives make it an attractive candidate for replacing adjustable speed ac and do drives in both industrial and consumer applications. Furthermore, a simple, low cost and robust SRM drive can be efficiently operatied ill the hostile environment of an automobile. In this paper, novel topology for fast response of various load is proposed. Proposed topology adapts anti-windup PI controller at increasing speed referense and activate braking mode at decreasing speed and forward load, Experiental results show that proposed topology have fast response charecteristics at increasing and decreasing speed reference.

In this paper the comparison of conventional PI control and nonlinear sliding mode control is presented for Switched Reluctance Motor(SRM). SRM drives require a nonlinear controller for high dynamic Performance but the high nonlinearity makes a poor performance in conventional PI control. However SRMs with sliding mode control achieve a robust performance for speed control. In this paper nonlinear sliding mode controller is suggested for high performance speed. State equation and modeling are proposed. And we present the speed comparison of PI control and SLMC.

Switched reluctance generators(SRGs) attract much attention in the generator because of high efficiency, simplicity, and ruggedness. They require rotor position information In determine the turn-on and turn-off angle, but the rotor position sensor is less tolerant of extreme environmental conditions, such as high temperature or dust, so the position sensor is limited and undesirable. This paper describes a new approach to estimate the rotor position from the measured terminal voltages and currents of the SRG. The proposed method is based on the instantaneous inductance of the SRG. The proposed method is verified by computer simulations and experiments.

Switched Reluctance Motors(SRM) are a promising candidated automotive drives of the next generations. The successful commercialization of SRM drives in automobiles depends highly on the developments of SRM design and control techniques. This paper descrives the control issues of SRMs, ranging from drive system structure, rotor position sensing and torque control. Both simulation studies and test results are presented for a 160W SRM drive for automotive application.

An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system(3-5kVA) that interface with a 220V single phase utility connection. As the result of this investigation, a 3kVA high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier. four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors, a net size, weight, and parts cost saving result compared to the other systems due to elimination of 60Hz transformer.

In this paper, we applied the Utility Interactive Photovoltaic-Wind Hybrid Generation System for stock raising waste disposal system. For the power consumption reduction of proposed system, we used the electromotive control system. So as to verify the propriety of proposed system, we made a Pilot Plant and examined the system.

Currently there are very limited amounts of resources and serious amounts pollution. Wind power generation system have an advantage of unlimited and unpolluted amount of energy resource. In this paper, for the application of these characteristic and for the generation to be achieved regard of districts and geographical features the energy continuously. The operation characteristics of system were analyzed through experiments for a trial product.

Photovoltaic and wind power generation have an advantage of unlimited and unpolluted amount of energy resource. In conventional wind generation systems, since the blade rotates at low speed when the velocity of wind decreases their operations are possible only under limited conditions. Therefore they are in trouble of self-generation without the help of auxiliary generation devices outside. The system driven by the wind force in this paper consists of a generator, an invertor, batteries and sets for power storage with a spring. In this paper, the operation characteristics of system were analyzed through experiments for a trial product.

Photovoltaic System does military exploit that use heliometer light and is clearness source of energy. Photovoltatic System is no noise, shock among is several Substitute energy and after establishment maintenance having simple special quality, is applied in many fields. However, while Photovoltatic System is having these advantage, but react sensitively in effect of Photovoltaic scanning Quantity, temperature change etc.. surrounding environment, when did not satisfy condition, express indefinite output price. Consider voltage$\cdot$current output measurement value and temperature revision calculation by temperature change of existing photovoltaic system and change of output price of when did Simulation analyzed comparison.

In this paper, the virtual implement of solar cell was proposed to solve the problems as reappearance and repetition of some situation in experiment of photovoltaic. To realize the VISC, mathematical model of solar cell for driving converter was studied and the buck converter were compared in viewpoint of tracking error of characteristic curve of solar cell using computer simulation.

The solar energy is purity and infinity. Solar power converter were used to convert the electrical energy from the solar arrays to a stable and reliable power source. So much country research this solar energy system. The photovoltaic system is construct many solar cell array, In this paper, new implementation solar system was showed buck converter that V-I curve produced. This system can be used to study the short-term and long-term performances of solar cell and efficiency. This system is a far more cost effective and reliable replacement for field and outdoor flight testing. Study of buck converter, analysis and control shun t$\cdot$series connection characteristics of solar cell array.

Voltage harmonics resulting from current harmonies produced by the nonlinear loads have become a serious problems in many systems. Moreover momentary interruptions and voltage sags are responsible for many of the power quality problems found in typical industrial plants. In this paper, proposed power quality compensate system using photovoltaic system is not only for harmonic compensation but also for harmonic isolation between supply and load, and for voltage regulation and unbalance compensation. Through computer simulations, we have verified the effectiveness of the proposed system.

In the power system of a satellite, solar array and a battery have directly impact on the life time of the satellite, and their stable operation is decided by whether their states are in the steady state operation or not. In this study, solar array capacity and battery characteristics of proposed communication satellite are designed and simulation is conducted according to the operation mode. Each operation mode is classified as the normal and worst case modes, respectively. The normal mode is analyzed under daylight and the eclipse with the EHT burn, and the worst case modes which have solar cell circuit failure, and battery cell failure are analyzed too.

In this paper, a new line-commutated SCR inverter for renewable power generation system is proposed. The proposed inverter system includes a 6-pulse SCR inverter and an auxiliary circuit. By the proper operation of the auxiliary circuit, the pulse number of the inverter system is increased and the output harmonic currents are reduced. Analysis, control and simulation for 24 pulse operation of the proposed scheme is presented and the experimental results will be provided in the final paper.

This paper suggests the circuit topology to transfer AC power using a detachable transformer The circuit topology for AC output load through the magnetic coupling and its principle of operation are described. It can decrease the size of detachable transformer by employing the high-frequency magnetic coupling. It is shown in this paper that the efficiency of noncontact energy transfer system can be improved by applying both the full bridge converter with PFC function to the 1st side of its and the series resonance to the 2nd side to minimize the effect of the leakage inductance.

As a batch Type device, this machine is contrive to seal glass plates for plasma BLU (Back Light Unit) by indirect heating from electric heaters. In order to maintain the heating / cooling Chambers clean, this machine uses a muffle formation. The components of the machine are listed bellow.

본 연구에서는 3상이 불평형된 전원 조건하에서 비선형 부하전류를 유효성분, 기본파 무효성분 그리고 왜 형성분으로 분해한 후, 능동전력필터를 제어할 수 있는 새로운 평균전력 알고리즘을 제시하였다. 제안된 방법의 타당성을 입증하기 위해, $15\%$ 불평형된 3상 전원 전압하에서 실험을 수행하였으며, 종전의 평균전력 알고리즘에 비하여 새로운 평균전력 알고리즘의 유용성을 입증할 수 있었다.

This paper represent about design of the controller for battery of a PE drum for power supply using PV Module. Simulation is represents V-I and power characteristic by Mathematica & Pspice 6.0 & Qnet 2.1. Finally, we composed of road surface-signpost system. This system is successfully operating with high clearness lights.

In this paper, comparing and analyzing the distribution of brightness as domestic lamps and Japanese products go thinner and lighter, we set an effective design standard. By comparing and analyzing the feature, brightness, chromaticity and uniformity of domestic LGPs and Japanese products, early home-manufacturing and stabilization in home-manufacturing are possible. By comparing and analyzing the distribution of brightness as sheets are varied, we can design an ideal sheet composition.

Exhaustion and environmental problem are big problem of 21th century is flint energy and the importance of energy to alternate flint energy as being risen is embossed more. Photovoltaic system is occupying big flow along with wind force development among is many substitute energy has shortcoming that energy conversion efficiency falls behind than another thing substitute energy, This research investigates electron beam to specification energy to Module that was generalized and schematized difference of curved line after existing V-I efficiency characteristic curve and irradiation. And will analyze cause of Module's efficiency addition and subtraction by electron beam investigation.

In the Electric Vehicle(EV) driving system, the Battery Management System(BMS) is very important and an essential equipment. Particularly, BMS monitors the State of Charge(SOC), voltage, current, and temperature of the battery modules when Electric Vehicle is in the state of motoring or charging. Major roles of BMS are like these the first, estimation of State of Charge(SOC), the second, detection of the unbalance of the voltage between battery modules, the third, control of the available limit of the voltage and temperature of batteries by monitoring the batteries status during motoring or charging. In this research, We have focused on estimating SOC of battery according to the status of Electric Vehicle and the BMS operation algorithm. The result for algorithm of SOC estimation is presented. It have been modified, compensated, and verified by means of the experiment.

For multi-carrier communication system, power amplifier generate intermodulation products caused by their nonlinear characteristics. Intermodulation products arised around the carrier frequency cannot be filtered out, operate as noise source for tile adjacent channel and thus degrades the quality of communication. In this paper, the 1850MHz-band RF linear power amplifier has been designed and fabricated with feedforward loop. The error signal loop consists of several key components such as phase shifter and attenuator, subtracter. The proposed Linearizer was tested with two-tone signals separated 10MHz apart at the center frequency of 1850MHz. The experimental results show C/I improvement by 14.5${\~}$20dB over 15dB dynamic range(33${\~}$47.8dBm) which gave IMD of 53.25${\~}$59dBc for the designed LPA.

가상현실 기술을 이용한 컴퓨터 지원 교육훈련 시스템 (VR-CATS: Virtual Reality based Computer Assisted Training System) 개발에 대한 연구를 전력연구원에서는 계속 수행해 왔다. 본 논문에서는 New VR-CATS (울진 3호기 참조)중 가상현실에서의 공동 협동 훈련 시스템(Virtual Reality Collaboration Training System)의 설계에 관하여 서술한다. 공동작업은 발전소 MCR(Main Control Room)을 3D 데이터 모델링 후 가상현실화하고 MCR 내부를 Navigation 할 수 있도록 가상패널(Virtual Panel)을 개발 및 에에 대한 엔지니어링 데이터베이스환경을 작성하여 추후 정확하고 신속한 계기 정보를 얻을 수 있도록 하며 훈련생들이 시뮬레이터실로 가지 않고 MCR에서 발전소를 운전하는 것과 같은 효과를 강의실에서 얻을 수 있다. 또한 설계기준사고 중의 하나인 LOCA 사고 복구 훈련 시나리오를 통하여 실제와 동일한 복구 훈련을 하므로서 효율적이며 현장감있는 교육훈련 수행을 가능케 한다.

심야전력요금제도의 정착으로 최근 심야전력축열기기의 보급이 활성화되고 있다. 그러나 모든 심야 전력축열기기들이 심야요금개시시간대인 22:00경에 동시에 가동됨에 따라 23:00에 심야전력 부하가 최대에 이르러 전력피크가 발생하여 한전의 수요관리에 큰 어려움을 주고 있다. 따라서 이 피크 부하를 심야전력 공급시간대의 저부하시간대로 분산시킬 수 있는 심야 전력축열기기 통전시간제어가 필요하게 되었다.

The accurate identification of the motor parameters is crucially important to achieve high dynamic performance of induction motors. In this paper, the motor parameters such as rotor resistance, stator(rotor) leakage inductance, mutual inductance are measured for torque monitoring and indirect vector control. To demonstrate the practical significance of the results, some experimental results are presented.

Recently, according to developing industry and life style, power consumption have been increased year after year. Currently these much power demand from power consumer weakening the allowable power reverse margin in summer. As on of the remedies about this problem, the small scale grid-connected photovoltaic system is considered for auxiliary power source. Generally, grid-connected Inverter have a isolation transformer for electrical isolation from utility. This paper proposed transformerless system topology an inquiry validity simulation.

This paper presents a study on successive approximation measurement of mechanical parameters for motor control system. At the first step of servo system installation, control system gain tuning is troublesome work. Recently, autotuning method of motion controller for motor drive system is based on parameter measurement and identification. On the case of first order mechanical system (mechanical parameters are modified by simple inertia and friction), it is necessary for good response to get the accurate measurement or identification of the mechanical parameters . In this paper, novel method applies the binary successive approximation measurement to the inertia and friction coefficient. Computer simulation and experiment for the proposed method will show verification of accuracy and usefulness.

In this paper the electromagnetic torque developed in IPMSM(Interior Permanent Magnet Synchronous Motor) is analyzed. If flux distributions in the motor are not sinusoidal, a sinusoidal current produces important torque ripple. Torque ripple causes vibration and noise of motors. The optimized current waveforms for ripple free is able to be obtained by analysis of Back-EMF and torque equation. The method to find the optimal current is based on numerical predetermination. In this paper proposes current waveform which can eliminate the torque ripple, and the validity is verified through the simulation.

전기집진기는 여타의 집진 설비에 대한 집진 효율과 유지 보수성이 우수한 설비이며 소결공장의 배출분진과 같은 고온($120{\~}160^{\circ}C$)의 미세분자($5{\~}12{\mu}m$) 및 고비저항($10^{12}{\~}10^{13} {\Omega}cm$)을 포집할 때 DC 하전에 비해 Pulse 하전이 효과적이며 Energy 절감이($60{\~}90\%$) 된다. 본 논문은 소결공장의 DC 하전에서 Pulse 하전으로 전환 시 EP 특성 및 부하변화에 따른 제어방안을 제시한다. 현재 제철소의 소결 전기집진기 경우 정수 직후에는 전압이 정상적으로 공급하다가 시간이 지남에 따라서 DC 전압이 낮아지고 Back Corona 현상이 발생하여 서서히 분진농도는 급격히 상승하는 문제점을 가지고 있다. 이에 비해 Pulse 하전으로 운전할 경우에는 Back Corona 현상 발생억제로 출구농도 상승 기울기를 조장방법 및 Ramping 장치와 관련장치 등을 최적으로 운용할 수 있는 방법을 소결공장 실험하였다.

This paper propose a new active common-mode voltage damper circuit that is capable of suppressing a common-mode voltage produced in the PWM VSI. The new active common mode voltage damper is consisted of a half-bridge inverter and a common mode transformer with a blocking capacitor. Principle of the active common mode damper is as follow; by applying the compensation voltage which has the same amplitude and opposite polarity to the PWM inverter system. So, common mode voltage and high frequency leakage current can be reduced. Simulated and experimental results show that common-mode voltage damper makes contributions to reducing a high frequency leakage current and common-mode voltage.

In this paper, the Load Current Observer Design for 3-phase Voltage Type PWM Converter with DC Meter Load. The sinusoidal input current and unity input power factor are realised based on the estimated source voltage performed by the Load Current Observer using actual currents and DC link voltage.

This paper is proposed an efficiency optimization operation algorithm for synchronous reluctance motor (SynRM) using current phase angle control technique. The SynRM has to controlled with the optimal current phase angles with load and operation speed variation, to obtain high efficiency over the wide speed ranges. An efficiency optimization condition in SynRM which minimizes the copper and iron losses is derived based on the equivalent circuit model of the machine. The objective of the efficiency optimization control algorithm compensating the optimum current angle, is to seek a combination of d and q-axis current components which provides minimum losses at a certain operating point in steady state. The usefulness of the proposed efficiency optimization control is verified through vector-controlled inverter system with the SynRM.

In this paper, a two-level switching algorithm ov the deadbeat to control PWM inverter is proposed. A modified algorithm of the deadbeat is suitable for the UPS system. Two levels in the pulse pattern are used. This scheme allows the use of higher switching frequency for a given computation time delay, which results in lower total harmonic distortion at the output. The proposed control scheme is implemented using TMS320F240 DSP for controlling on inverter.

In PCB assembling line, it needs SMD mounter. In this paper, the feeder of the SMD mounter, which carry component to the mounter is designed. Up to now, mechanical air feeder is mainly used. But in these days, it is developed to the electrical feeder with network. There are many kind of feeders with various control technique. In this paper, the feeder with BLDC motor and LON chip is designed and implemented. Then the experimental results are presented.

In this paper, a new detection algorithm of faulted voltages under the unbalanced condition and a control algorithm of the instantaneous voltage sag corrector (IVSC) are proposed. To quantify the unbalance under fault conditions, the voltages are decomposed into two balanced three-phase systems using the symmetrical components of positive and negative sequence voltages, which is defined by magnitude factor (MF) and unbalance factor (UF). New control algorithm based on MF and UF values for instantaneous voltage compensation are proposed and verified through the PSCAD/EMTDC simulation and experimental results.

Of two photovoltaic systems such as stand-alone type and utility interactive one, the utility interactive systems are so valuable for power peak-cut particularly in summer season. For the maximum power point tracking(MPPT) by which the generated energy can be maximized, many control methods have been reported up to now. To overcome the disadvantages of the conventional ones, a new MPPT algorithm is proposed which can improve both tracking ability and generating efficiency of photovoltaic system without chopper.

In this paper, we have developed a new Force-Display system using tendon-driven method based multiple DC motors. The proposed system is based on the HIR Lab Haptic library, which calculates the real position and renders the reflecting force data to device rapidly. The system is composed of device based tendon- driving method, high-speed controller and Haptic rendering library. The developed system will be used on constructing the dynamical virtual environment. To show the efficiency of our system, we designed simulation program, which an display the moving force (attaching, grabbing, rotating) on two virtual points. As the result of the experiment, our proposed system shows much higher resolution than any others.

A new phase-shifted parallel-input/series-output dual converter for high-power step-up applications has been proposed. It features a high efficiency due to the low switch turn-off voltage, low device stresses, low ripple contents, and a fast control-to-output dynamics compared to its PWM counterpart. To confirm the validity of the proposed converter, experimental results from an 800W, 350Vdc prototype are presented.

This paper describes an improved short-circuit protection for a multilevel ac/dc power converter The output do power of the proposed converter can be disconnected from the load within several hundred microseconds at the instant of short-circuit fault. Once the fault has been cleared the dc power is reapplied to the load. The rising time of the do load voltage is as small as several hundred microseconds, and there is no overshoot of the dc voltage because the do output capacitors hold undischarged state. Therefore, the proposed converter can be used for a power supply, which requires a rapid disconnection of the load from the power supply in the case of a short circuit, as well as a rapid connection the load to the power supply after the clearance of the short circuit condition.

This paper presents a PWM buck AC-AC converter with instantaneous compensation for input voltage sag and surge. The presented converter use commercial IGBT modules and its output voltage is regulated so as to remain constant AC output voltage. The feedforward control technique is also proposed to establish instantaneous duty level change whereby stable output voltage will be retained. This paper show the characteristics and control algorithm of the converter through various PSPICE simulations.

In this paper, a single-phase to three-phase PWM converter topology using six switches only for low cost induction motor drive is proposed. The converter topology is of lower cost than the conventional one, which gives sinusoidal input current, unity power factor, dc output voltage control and bidirectional power flow In addition, the source voltage sensor is eliminated by controlling the deviation between the model current and the system current to be zero. The performance of the proposed converter has been demonstrated through the computer simulation.

A new single stage power factor corrected AC/DC converter has been proposed, that is unified with buck topology and suitable for universal input. The design example of the proposed converter lot 5V 12A application has been presented. The design considerations and simulation results for the proposed converter have been shown. The simulation results show that the line input current harmonics can meet IEC 1000-3-2 Class D requirements for the line input voltage from 90 to 260V.

This paper introduces a ZC-ZVS PWM(Pulse-Width -Modulation) boost converter. The IGBT(main switch) of the proposed converter is always switched at ZCS and soft switching of MOSFET(auxiliary switch) as well. Therefore, the proposed converter minimized the turn on/turn off switching losses of switches and reduced conduction losses by using IGBT switch. Moreover, using paralleled IGBT-MOSFET switch overcame the switching frequency limitation. Therefore high power density system can be realized. As mentioned above, the characteristics are verified through experimental results.

This paper is proposed a sinusoidal input current multi-level ac-dc converter using transformer. The multi-level converter which controls input current by combining Buck converter to Improve input current characteristics. This method, which is multiplying and duplicating output of converter of equal capacity, is able to control unit power factor of input current, reduce the problem caused by high frequency switching, and apply to high power converter because filter is not necessary The feasibility of the circuit is verified by computer simulation using PSIM

In this paper, we firstly proposed to the boost type PFC circuit for a power factor improving and a harmonic decreasing. The predict current control method is used to control these PFC circuit. This current control method has a merit that is possible to improve power factor and harmonics. In addition, we suggested to the active DC filter, which is connected with the DC output terminal, in order to compensate the DC ripple components. Consequently, these results are proved by the simulation tool, PSIM, which is an exclusive simulator of power electronics.

In this paper, dc link ripple currents for three-phase ac/dc/ac PWM converters are analyzed in a frequency domain. The expression of the harmonic currents is developed by using switching functions and exponential Fourier series expansion. The dc link ripple currents with regard to power factor and modulation index are investigated. In addition, the effect of the displacement angle between the switching periods of line-side converters and load-side inverters on the do link ripple current is studied. The result of the do link current analysis is helpful in specifying the dc link capacitor size and its life time estimation.

A new control method of three phase converter without measuring input Phase-voltage and DC-link voltage is Proposed. Input Phase-voltage of these required voltages is estimated using EKF(Extended Kalman Filter) and DC-link voltage is estimated from the measured line currents and the estimated input phase-voltage. This control method is achieved without PLL(Phase Locked Loop) which senses the angle of input phase-voltage and DC-link voltage sensor. In additon, the proposed method controls high power factor and DC-link voltage utilizing the estimated phase angle. This paper describes the effectiveness of the proposed estimated algorithm through simulations.

The torque of SRM depends on phase current and the derivative of inductance. But the inductance of SRM is nonlinearly changed according to rotor position angle and phase current because of saturation in magnetic circuit. Therefore this has a concern in torque ripple and speed variation, and it is difficult to control the desired torque The torque of SRM depends on phase current and the derivative of inductance. But the inductance of SRM is nonlinearly changed according to rotor position angle and phase current because of saturation in magnetic circuit, and it is difficult to control the desired torque. This paper proposes an optimization control scheme by adjusting both the turn-on and turn-off angle according to high efficiency points which are simulated by GA-Neural Network, which is used to simulate the reasonable switching angle which is nonlinearly varied with rotor speed and load.

A novel single-stage power factor corrected (PFC) drive for switched reluctance motor (SRM) is presented to achieve sinusoidal, near unity power factor input current. The proposed PFC SRM drive has no additional active switch. And a single-stage approach, which combines a DC link capacitor used as dc source and a drive used for driving the motor into one power stage, has a simple structure and low cost. The characteristics and validity of the proposed circuit will be discussed in depth through the experimental results.

Energy recovery in the regenerative region is very important when SRM(Switched Reluctance Motor) is used in traction drive. This is because that to reduce energy toss during mechanical breaking and/or to have a high efficiency drive during breaking. To control excitation voltage in motor operation and regenerative voltage in the generator operation in the SRM, multi-level voltage control is effective. This paper proposes multi-level inverter which is useful for motoring and regenerative operation in SRM. The proposed method is verified by experiment.

The control of the SRM(Switched Reluctance Motor) is usually based on the non-linear inductance profiles with positions. So determination of optimal switching angle is very different. This paper proposed that the determination method of turn-on/off angle in the SRM drives is to maintain the high torque, which is realized by using self-tuning control method. During the sampling time, a number of pulses from the encoder are checked by using micro-controller. And compared with pre-checked a number of pulses. After calculating difference between two data, turn-on/off angle moves forward or backward direction by using self-tuning method. The optimal turn-on/off angle is determined by iterating such a process and the maximum torque is maintained. Experimental results are provided to demonstrate the validity of the self-tuning controller.

Universal motors are mainly used for vacuum cleaner application. There are a lot of researches on SRM that applys home appliance throughout the world. The manufacturing cost of SRM drive makes it hard to expand its application to home appliance. This paper presents Single Phase SRM for the vacuum cleaner that has advantge in cost and performance over conventional universal motor. This paper proposes new power device driving scheme by using SRM switching characteristic. The driving scheme is very simple and inexpensive. Dwell Time Control method is used for the minimum switching loss of power device. The switching frequency of power device is less than 4.5kHz at 45,000rpm. By use of this scheme, power device based on very small switching losses can be used on SRM drive. Also, the biggest problem in single phase SRM is starting, this paper shows a new starting algorithm with two hall sensors, accelerating and running sensors, respectively. Finally, the proposed Single Phase SRM achieves higher efficiency and long life time compared to universal motor. Its life time is more than 1500 hours. Its life time is extended 4 times than that of conventional motor and its suction power is increased $20\%$ at the same volume of conventional universal motor.

In this paper, a mathematical model of permanent magnet synchronous motor (PMSM) fed by inverter with Direct Torque Control (DTC) Dynamic and steady state characteristics of PMSM is simulated and analyzed: electro-magnetic torque response, speed response, locus of the stator flux linkage. It is mathematically proven that the increase of electromagnetic torque in a permanent magnet motor is proportional the increase of the angle between the stator and rotor flux linkages, and, therefore, the fast torque response can be obtained by adjusting the rotating speed of the stator flux linkage as fast as possible. The simulation results verify the proposed control and also show that the torque response under DTC is much faster than the PWM current controlled drive.

An increase of pulsed power demand and load variation produce bad effect to power system. This causes power factor decrease. This paper proposes the excitation of the secondary side of wound rotor induction machine as one of harmonic compensation systems. In this paper, a harmonic compensation scheme based on stator flux-oriented vector control is proposed. By using the flux-oriented vector control, a voltage source PWM(Pulse Width Modulation) control scheme can be applied with fast dynamic response time. The designed control scheme is verified through simulation.

In this paper, we experimentally considered the stability of AT forward MRC with the characteristics of high efficiency and high power density. The converter ratings are input 48V, output 5V/50W, The maximum voltage stress is measured to about 170V of 2 times the input voltage when the input is 58V. The $81.66\%$ of maximum efficiency could be obtained. For the stability of the converter, it is compensated through the error op amp in MC34067. A phase margin and a gain margin for relative stability are measured using HP4194A network analyzer.

Direct Torque Control has the fast torque and flux dynamic response as we know. This dynamic performance is realized by the estimation of electromagnetic torque and stator flux linkages. Generally, the stator flux estimation is based on the stator voltage equation. The equation uses a pure integrator. If the equation is used without an encoder in Direct Torque Control, there is the drift problem. It is same to sensorless Stator Flux Orientation Control (SFO). In this paper a programmable low pass filter (LPF) is proposed for solving the problem in Direct Torque Control.

This paper describes the power factor control of doubly fed induction machine using fuzzy logic algorithm in wind power generation system. Under fuzzy logic control, which enables superior dynamic performance, the power factor is independently controllable by decoupled d, q rotor experimental results are presented.

In this paper, author consider the nonlinear control by using feedback linearization for independent control and estimation algorithm such as speed, rotor flux and rotor resistance to achieve sensorless control of induction motor. The dynamic characteristics of the proposed nonlinear control algorithm is verified by simulation.

Direct torque control(DTC) is known to produce quick response in ac drives. Some drawbacks of the classical DTC are the relatively large torque ripple in a low speed range and notable current pulsation during steady state. They are reflected speed response and increased acoustical noise. In this paper, The DTC quick response are preserved at transient state, while better qualify steady state performance is produced by Space Vector Modulation(SVM). It is able to reduce the acoustical noise, torque ripple and current pulsation during steady state. The system presented are closed loop stator flux and torque observer for wide speed range that inputs are currents and voltages sensing of motor terminal. Simulation results for the 2.2kw general purposed induction motor are presented and discussed.

The crane operates in three directions, hoisting, traversing, and travelling motion. In this study, an AC drive system for these motions of the crane is developed and tested. The command from an operator is transmitted to PLC, which sends data to a main controller by fieldbus protocols such as Profibus or Devicenet. And the main controller is connected to other auxiliary ones by CAN bus. The each controller, which has the same structure, regulates its motor speed from the operator's command.

In the System-integrated modular advanced reactor(SMART), the motor for Control element drive mechanism(CEDM) requires high density power and simple drive mechanism to reduce volume because of restriction by install-space and must satisfy the reactor operating circumstances with high pressure and temperature. To Maximize the characteristics of the TFM, we chose the asymmetric bridge converter as the driving system for TFM. Because two switching devices are connected in series with the stator winding of each phases in the asymmetric bridge converter all the phases are not affected by another phase but controlled independently. Also, this converter has many advantages that the various control methods can be adopted, it is easy to control, and that in case that the switching devices of a phase are damaged, the affects can be minimized.

In steel plant, load torque of mill driver motor is changed periodically because working state and idle state are repeated and load current of working state is necessarily higher than rated motor current. The over current limiter is one of the basic thermal protection method from over heating. In this paper, we analyzed the structure of over current limiter for motor and motor driver systems, developed over current limiter with same operation and structured warning system of action of over current limiter. As using this warning system, we can avoid abrupt plant stop by over current limiter in mill driver and lessen producing loss by plant stop. The developed warning system of action of over current limiter is exactly inspected by computer simulation md analysis of acquired data.

This paper describes the implementation of UPS system controlled by the DSP. The digital techniques have been used tn overcome the problems of UPS system controlled by analog control circuits. By developing these systems using the digital technique we could increase the reliability and improve the electrical characteristics. And we designed and developed the system which is able to control UPSs and to monitor errors, statuses and actual values transmitted from UPS through internet. The UPSs also impose high demands on battery life time, reliability and energy-efficiency. These requirements can only be met by employing sophisticated battery management system(BMS). Therefore, a highly accurate, universal and inexpensive measuring system for BMS was developed.

In this paper, the minimization of particle wit introduction of face to face to face type in cleaning. Easy input and change of parameter Monitoring function of process data in process function of 3 moving axis. Return Tank for Chem cal solution

This paper presents a forecasting method for production volume of each model manufactured goods by using Back-Propagation technique of Neural Networks. As the learning constant and the momentum constant are respectively 0.65 and 0.94, the learning number is the least, and the forecating accuracy is the highest. When the learning process is more than 1,000 times, the accurate forecating was possible regardless of kind of product.

In this paper, a method which can detect tracking caused by the insulation deterioration of conduct wiring, is proposed. The computer which take experiment data is learned by neural network algorithm, which has recently been used for the load recognition. The proposed method in our study can be applied to the development of several measuring equipments such as hot-line insulation tester, car earth tester for the detection of tracking under hot-line state.

In this paper, the basic characteristics of flat fluorescent lamp using ultraviolet generated from gas discharge and powder type electro luminescent display using a phenomenon of the light emission caused by the electrical field applied to phosphor are studied. The lamp is a simple structure with insulator layer, phosphor layer, and gas gap. Current(displacement current + discharge current) in flat fluorescent lamp using.

Most of the battery charger for electric powered forklift truck are controlled by the method of 3-phased constant current and constant voltage. However, these chargers have several disadvantages like a large charger capacity, and a short battery life time. This paper presents a digital type battery charger based on multi-mode control adding a constant power control and several assistant controls in the conventional control. The whole control system is performed by a low cost one-chip micro-controller and completely digitize. So we can get a high precision control and a good reliability.

Water-Electrolyzed gas is a mixed gas of the constant volume ratio 2:1 Hydrogen and Oxygen gained from electrolyzed water, and it has better characteristics in the field of economy, efficiency of energy, and environmental intimacy than acetylene gas and LPG used for existing gas welding equipment. So studies of Water-Electrolyzed gas are activity in progress nowadays, and commercially used as a source of thermal energy for gas welding in the industry. The object of this paper is V-I feature of Hydrogen -Oxygen Gas Generator using DC source

In this paper, the basic characteristics of flat fluorescent lamp using ultraviolet generated from gas discharge and powder type electrolyminescent display(P-ELD) using a phenomenon of the light emission eaused by the electrical field applied to phosphor are studied. The lamp is a simple structure with insulator layer, phosphor layer, and gas gap. Current(displacement current + discharge current) in flat fluorescent lamp using.

In this paper, a 3phase-3wire series active power filter compensating current harmonics and unbalanced source voltages is presented. The system is composed of series active power filter and shunt passive filters that are tuned 5th and 7th harmonics. In this system, series active power filter improves harmonic compensation characteristics of the shunt passive filters and compensates the unbalanced source voltages. In the proposed algorithm, compensation voltage for harmonic reduction is calculated by a performance function, and compensation voltage for the unbalanced source voltage is calculated in based on the synchronous reference frame. Some results obtained from the experimental model using the proposed method are presented to demonstrate and confirm its validity.

In this paper, the proposed current control algorithm is analized and discussed about how to design the auxiliary circuit with auxiliary switch which can apply ZVT operation for the main switch. The simulation results would be shown to verify the proposed current algorithm, because the main power switch is turn on with ZVT and the bi-directional Inverter is operated.

본 논문에서는 고압 대전력 3상 유도전동기의 고정자 권선을 이용한 전압원 인버터의 병렬운전 방식을 제안한다. 현재 사용되고 있는 대부분의 4극 이상 대전력 유도전동기는 각 상의 권선이 외부에서 접근이 가능하도록 외부단자가 설치되어 있으며, 이들 외부단자를 이용하여 복수대의 전압원 인버터를 병렬운전하여 대전력 유도전동기를 구동할 수 있다. 이와 같이 고압 대전력 유도전동기를 복수 개의 전압원 인버터를 병렬 운전하여 구동할 경우, 특정 인버터의 고장발생 시 비록 구동 토크는 감소될지라도, 나머지 인버터로 시스템을 계속 구동할 수 있어 시스템의 고장대처능력을 향상시킬 수 있다. 또한 병렬 운전되고 있는 각 인버터의 스위칭 동작에 대해 서로 위상 차를 갖게 함으로서, 등가 스위칭 주파수를 증가시켜 출력 토크 리플 감소와 입력 전류 리플 감소, DC Link 커패시터의 크기 감소와 같은 좋은 특성을 얻을 수 있다. 또한 각 인버터로의 전력의 분산에 의해 시스템에서 발생하는 EMI 영향을 감소시킬 수 있다. 본 논문에서는 제안한 방식을 컴퓨터 시뮬레이션을 통해 특성을 증명하였다.

The voltage resonating inverter has a defect in switching element that works at 5 or 6times higher than input voltage. Especially, it is very difficult to choose the switching device is very high for the 220(V)commercial voltage. In this paper, it is proposed the optimum method to realize the turbo 2000(W) power for induction cooker that is employed the 900(V) IGBT with decreasing operating voltage of the switching component by making the 220(V), 1500(W) inverter through the claim mode voltage resonating inverter.

The recent advancements in power electronic switching devices have enabled high frequency switching operation and have improved the performance of pulse-width modulated (PWM) inverters for driving induction motors. But, the insulation failures of stator winding have attracted much concern due to high dv/dt of IGBT PWM inverter. In this paper, the test results for evaluation on the stator winding insulation of low-voltage induction motors for IGBT PWM inverter applications are presented. The insulation characteristics are analyzed with partial discharge and dissipation factor tests. Also, insulation breakdown tests by switching pulse voltage are performed. An effective insulation technique to enhance the insulation strength is suggested from the test results.

LCD 모니터 화면의 대형화와 슬림화에 따른 모니터 내의 백 라이트용 냉음극 방전램프(CCFL)도 가늘어지고 길어지고 있으며, 하나의 램프를 이용한 백 라이트로는 휘도의 한계가 있어 램프를 병렬로 사용해 필요한 휘도를 만들고있다. 멀티램프 구동용 인버터는 소형, 고효율화 뿐만 아니라 대출력이 요구된다. 방전램프가 정밀하고 동일한 제작 과정을 거치더라도 점등, 주파수, 전압, 전류 등 여러가지 특성이 동일하지 못하다. 이는 각기 상이한 램프특성 때문에 초기 점등조건이나 점등 후 동일한 휘도를 갖기 어렵다. 본 논문에서는 멀티램프를 최소의 인버터 개수로 같은 입력조건에서 같은 출력을 갖도록 설계한다. LCD 모니터 내부에 상하각 2개씩 4개의 램프를 내장하고 있는 18인치형을 이용하였다. 하나의 구동용 인버터를 이용하였으며, 결과적으로 $90\%$이상의 휘도대비 입출력 효율을 얻었으며, 램프간의 출력차이가 미소하여 상용화 가능하며, 또 다른 방전램프의 멀티구동에 이용 가능하다.

A high frequency resonant inverter consisting of three unit half-bridge serial resonant inverter used as power source of induction heating at high frequency is presented in this paper. As a output power control strategy, tine-sharing gate control method is applied. The analysis of the proposed circuit is generally described by using the normalized parameters. Also, according to the calculated characteristics value, a method of the circuit design and operating characteristics of the inverter is proposed. This paper proves the validity of theoretical analysis through the experiment. This proposed inverter show that it can be practically used in future as power source system for induction heating application, DC-DC converter etc.

In this paper, voltage-fed high frequency resonant inverter of instantaneous current phaser control method used to DC voltage source separated is proposed. In the output control method, a novel circuit type of phase shift driving signal method with CVCF illustrated, also the operation principle of the proposed circuit is described in detail and its characteristics are presented as to normalized parameters. According to the each mode, in order to the circuit analysis and characteristic evaluation of the state equation are derives and present used to normalized parameter. In the future, this proposed inverter show that it can be practically used as power source system for the lighting equipment of discharge lamp, DC-DC converter etc.

This paper makes a general description of the results at government project which were peformed for several years. Through this project, the real capacity of 3.3KV/4MW Class 3 Level Voltage Source Inverter System were designed and the characteristics of its proto type were analyzed, moreover the web based IIMS(Inverter Information Management System) and Virtual Operation Simulator was developed. Now, this system is running for field application test.

In this paper, the new control algorithm is proposed that compensates instantaneously the active and reactive components of the input currents by the synchronous d,q axis conversion of a single-phase current in controlling the single-phase AC/DC parallel converters for a high speed train. The leakage inductance of a transformer was used as a boost inductance and the ripple of a transformer's primary current was reduced considerably by the parallel operation of the two converters with a proper switching phase-shift. The stable and fast control response characteristic is certificated by a simulation.

The conventional 60(Hz) power supply for driving magnetron in microwave oven has disadvantages of heavy weight and low efficiency due to 60(Hz) High Voltage Transformer(HVT), capacitor and the phase control of thyristors with open-loop controller. To alleviate these disadvantages, this paper proposes a 20(kHz) phase-shifted(PS) Full-Bridge(FB) Zero- voltage-Switched(ZVS) PWM converter to drive a 600(W) magnetron in an 1(kW) microwave oven and to control the average anode current.

ZVS Full-bridge converter is widely used in medium power level(1-3kW). ZVS can be designed within a limited load range and ZVS failure at light load condition is assumed to be acceptable within the given efficiency and thermal constraints. However, unbalanced ZVS resonant energy caused by dc blocking capacitor may alleviate the switching loss problem at light load condition. ZVS resonant energy is unbalanced by do blocking capacitor. This problem causes loss and heat concentration of a switch leg, In this paper, this problem is analyzed, and a novel control method is proposed to solve the problem.

In this paper, the experiment and simulation results of the Boost converter for PFC(power factor correction) using metal powder inductor are presented. The metal powder inductor used in the experiment was composed of Ni-Fe-Mo, Ni-Fe, Fe-Si-Al compound respectively The performance of the 500w class PFC rectifier with the average current mode control and the 300W class PFC rectifier with the variable frequency control, are evaluated.

Due to several advantages of Pulse Width Modulation(PWM) Converter, such as unity power factor operation, elimination of low-order harmonics and regeneration of motor braking energy to source, the application range of PWM Converter has been rapidly extended in industrial application. Nowadays, vector control algorithm and space vector PWM(SVPWM) method are applied to improve the performances of PWM Converter, but vector control algorithm and SVPWM require to use Microprocessor and other digital devices in hardware, causing costly and somewhat large dimension system. In every practical application of energy conversion equipments, the design and implementation should be carried out considering cost and performance. High performance and low cost is the best choice for energy conversion equipments. So, this paper presents the practical design method and implementation results of 3-phase PWM Converter with analog hysteresis current controller, and verifies the performances of unit power factor operation and energy regeneration operation via experimental results.

The vestibular system located in the inner ear controls reflex body posture and movement. It has the semicircular canals sensing an angular acceleration and the otolith organs sensing a linear acceleration. With this organic signal, medical doctor decide if a person has disease or not. To obtain this data, a precision stimular system is considered. Robust control is needed to obtain eye signals induced by off-vertical axis rotation because of an unbalanced load produced by tilting the axis of the system upto 30 degrees. In this study, off-vertical axis rotatory system with visual stimulation system are developed. This system is consisted of head mounted display for generating horizontal, vertical, and three dimensional stimulus patterns. Furthermore wireless recording system using RF modem is considered for noiseless data transmission.

본 논문에서는 간단한 외란 관측 기법을 이용한 영구자 석형 동기 전동기(Permanent Magnet Synchronous Motor: PMSM)의 비선형 속도 제어 기법이 제안된다. 피드백 선형화 (feedback linearization) 기법을 이용함으로써 비선형 요소가 효과적으로 제거되고 출력 오차 동특성을 선형 제어 기법에 기반 하여 설정할 수 있다. 그리고 파라미터 변동에 의한 비선형 외란을 제거하기 위해 본 논문에서는 외란 관측 기법을 이용한다. 제안한 관측기를 이용한 비선형 속도 제어 알고리즘이 파라미터 변동에 대해 강인한 제어 특성을 가짐을 시뮬레이션으로 확인하였다.

In this paper, the gearless traction machine drive system using a permanent-maget motor for high-speed elevators is addressed. This application of permanent-magnet motor to the elevator traction machine enables several improvements including higher efficiency, better ride comfort, smaller size and weight, and so on. PWM boost converter is also adopted so that DC-link voltage regulation, hi-directional power flow, and controllable power factor with reduced input current harmonics are possible. To increase reliability and performance, the control board, which can include the car and group controller as well as PWM converter and inverter controller, is designed based on TMS320VC33 DSP The simulator system for high-speed elevators has been developed so that the drive system of high-speed elevator can be tested without my limitation on ride distance and the load condition. Some experimental results are given to verify the effectiveness of the developed system.

This paper presents neural load disturbance observer that used to deadbeat load torque observer and regulation of the compensation gain by parameter estimator. As a result, the response of PMSM follows that of the nominal plant. The load torque compensation method is compose of a neural deadbeat observer. To reduce of the noise effect, the post-filter, which is implemented by MA process, is proposed. The parameter compensator with RLSM (recursive least square method) parameter estimator is suggested to increase the performance of the load torque observer and main controller. The proposed estimator is combined with a high performance neural torque observer to resolve the problems. As a result, the proposed control system becomes a robust and precise system against the load torque and the parameter variation. A stability and usefulness, through the verified computer simulation, are shown in this paper.

This paper presents the sensorless control technique with cost competitive phase currents detection for PMSM drives. The phase currents are detected by two methods : one is from the do link current, another is from the currents of the lower legs of the inverter switches. The sensorless control with the phase currents dectection is implemented with DSP. It is verified through the experiment that the estimated rotor position tracks the real rotor position at the low speeds and high speeds operation with flux weakening.

This paper presents a implementation of digital sensorless position control system of surface permanent-magnet synchronous motor (SPMSM) drive with a direct torque control (DTC). The system are stator flux and torque observer of stator flux feedback control model that inputs are current and voltage sensing of motor terminal with estimated rotor angle for a low speed operating area, two hysteresis band controllers, an optimal switching look-up table, rotor speed estimator, and IGBT voltage source inverter by using fully integrated control software. The developed sensorless control system are shown a good motion control response characteristic results and high performance features using 1.0 (kW) purposed servo drive SPMSM.

본 연구에서는 표면 부착형 영구자석 전동기(PMSM)의 회전자 부착 자석 변동에 따른 영향과 변동위치를 검출하는 기법에 대하여 연구하였다. 회전자 표면부착 영구자석의 변동은 사용조건에 따른 변화와 자석 단품에 의한 영향으로 구분해 볼 수 있고, 이들 변화 요인 중 제어장치에 치명적인 자석에 의한 변화를 고려하였다. 따라서 자석의 변동 현상중 고밀도 자성체의 하나인 네오드늄_보론_철 계열의 고에너지적을 갖는 자석의 산화 방지를 위한 표면 부식 등의 현상에 의한 자편의 완전 이탈을 가정하고 이와 같은 이탈현상이 발생한 경우의 현상과 일반적으로 사용되는 인크리멘탈 엔코더를 적용한 이탈 발생위치를 추적하는 방법을 보였다.

This paper investigates the problem of the speed estimation of conventional speed sensorless stator flux-oriented induction machine drive in the field weakening region and proposes a new speed estimation scheme to estimate speed exactly in transients in the field weakening region. The error included in the estimated rotor speed is removed by not a low pass filter but Kalman filter.

When the vector control, which does not need a speed signal from a mechanical speed sensor, it is possible to reduce the cost of the control equipment and to improve the control performance in many industrial application. In this paper, describes a rotor speed estimate method of induction motor based on the theory of counter EMF MRAS. This method eliminated the pure integrator. and we can be expected to rapid responsibility of the speed Identification. Therefore, we improve the initial condition of the integrator and drift problem. The stability of speed estimator is proved on the basis of hyperstability theory. In order to confirm the performance of the proposed system. Simulation and experiment is performed.

본 논문에서 비교하는 두 시스템은 모두 전력계통에서 발생할 수 있는 고조파 전류를 효과적으로 보상할 수 있는 시스템이다. 전력계통에서 고조파전류는 계통전압에 장해를 주기 때문에, 프릿카나 각종 전력용 기기의 발열, 진동, 소음 혹은 유도잡음 장해등의 원인이 된다. 따라서, 이에 대한 대책이 중요한 문제가 되고있다. 본 논문은 이러한 고조파보상 시스템의 새로운 형태로써, 플라이휠에 의해서 만들어지는 에너지 저장시스템에, 전압형 PWM 인버터를 병용하여 순시제어가 가능한 시스템을 설계하는 것이다. 그리고 여기에 사용되는 회전기로 각각 권선형과 농형을 사용하여 시스템을 구성하고 그 특징과 장/단점을 비교 분석하였다.

In this paper, a novel design method of variable motor inetia in Induction motor drive system is proposed. The inertia of a load and a motor are estimated by using RLS (Recursive Least Square) algorithm. The speed controller is designed by Kharitonove theory of motor. The effectiveness of the proposed scheme is verified with simulation and experiments results.

권선형 유도전동기는 기동시에 충분히 큰 저항을 외부에서 삽입하여 기동전류를 작게하는 동시에 기동 토크를 크게 할 수 있다. 또한, 유도전동기의 각 기동 방식중에서 가장 우수한 시동특성을 가지고 있으며 크레인, 시멘트공장 등 중부하 시동이 요구되는 경우 널리 사용되고 있다. 권선형 유도전동기 드라이브 시스템의 전류, 토크, 위치 및 속도 등의 제어를 위하여 일반적으로 산업현장에서는 Pl 제어기가 많이 적용되고 있다. 그러나 이러한 시스템은 센서 부착시 여러가지 환경적 제약으로 인한 전체시스템의 성능 저하를 가져올 수 있어 이를 개선하기 위한 센서리스 벡터제어가 활발히 연구되고 있다. 본 논문은 권선형 유도 전동기의 센서리스 벡터제어를 위해 MRAS 기법을 적용하였고, 기존의 MRAS 기법 적용시 발생하는 파라미터 변동에 따른 속도추정오차를 개선하기 위해 센서리스 벡터제어의 속도제어에 크게 영향을 미치는 고정자 저항을 온라인으로 튜닝함으로서 파라미터 변화에 강인한 센서리스 속도제어를 구현하였다. 제안된 기법의 타당성 및 유효성을 디지털 컴퓨터에 의한 시뮬레이션에 의해 확인하였다.

This paper describes a control scheme for direct torque and flux control of induction machines. The proposed predictive flux control scheme has directly calculated the reference voltage space vector based on flux errors in order to control the torque and flux. This proposed control scheme has not the requirement of a separate current regulator and proportional-integral (PI) control of the flux, torque, and/or current error, thereby improving transient performance and also has the advantage of less torque ripple in steady state with a fixed switching period. The effect of proposed method has been proven by simulations.

When the vector control, which does not need a speed signal from a mechanical speed sensor, it is possible to reduce the cost of the control equipment and to improve the control performance in many industrial application. This paper describes a rotor speed identification method of induction motor based on the theory of flux model reference adaptive system. The estimator execute the rotor speed identification so that the vector control of the induction motor may be achieved. The improved auxiliary variable of the two model are introduced In perform accurate rotor speed estimation. The control system is composed of the PI controller for speed control and current controller using space voltage vector PWM technique. High speed calculation and processing for vector control is carried out by TMS320C31 digital signal processor. Validity of the proposed control method is verified through simulation and experimental result.

Much attention has given to EMI effects created by variable speed ac drive system. This paper focuses on the switching technique to mitigate common mode voltage. Zero switching states of inverter control invoke large common mode voltage. Using inversed carrier wave, zero switching states are removed. In addition, proposed technique is easy to apply to existing 2-level inverter design. Simulation results show that common mode voltages adapting proposed technique are reduced regarding conventional method.

Nonlinear loads change the sinusoidal nature of the ac power current, thereby resulting in the flow of harmonic currents in the ac power system that can cause interference with communication circuits and other type of equipment. To minimize the damage, it is needed to limit harmonics current and voltage. Harmonic measurement system was developed to measure individual voltage and current harmonic continuously and save harmonic data on computer. We measured all 154kV feeders in a steel making company substation. Voltage and current distortion limits for general transmission systems was suggested We found some feeders exceeded current distortion limits. As result voltage harmonic exceeded standard limits.

The sustaining driver for color ac plasma display panel should provide alternating high voltage pulses and recover the energy discharged from the intrinsic capacitance between the scanning and sustaining electrodes inside the panel. In this paper, a novel efficient energy recovery circuit employing boost-up function is proposed to achieve a faster rise-time and in order to obtain a stable sustain voltage. The principle of operation, features, and simulated results are illustrated and verified on an equivalent capacitance, which is equals In that of 40-inch-panel, 200 (kHz).

This paper presents the results of the power system analysis and power loss breakdown peformed on a 40-inch ac plasma display panel (PDP) TV set. The architecture and function of power system is reviewed. The power flow inside the PDP TV set is presented, and the distribution of the power loss is analyzed. It was found that the sustain driver circuit and power factor correction (PFC) circuit are the two major sources of the power loss. The results of this paper can be used as a preliminary guideline to improve the architecture and efficiency of power systems for ac PDP application systems.

This paper deals with the translation and terminology adjustment of international standard IEC 60050-551 for international electrotechnical vocabulary in the field of power electronics. The standard has been prepared by IEC Technical Committee 22 : Power Electroncis, under the responsibility of IEC Technical Committee 1 : Terminology and is consists of 9 sections with 221 terms. This paper contains the results for 150 terms among them.

Since recent inverters are formed IGBT VVVF inverter its switching speed has been increased relative to the conventional inverters and the motor design based on the switching surge voltage at the inverter output is very important factor. Therefore, motor and inverter should be designed to have the optimal characteristics by considering the mutually limited conditions. On this research the design technology characteristics for inverter driving traction moor is compared to the products in Korea and the analysis is performed. Thus, it is intend to re-estimate the technology level and introduce the products by HHI, which is driving on Seoul subway line 6 since December, 2000.

The advantage of the squirrel cage induction motor is the brushless rotor. This advantage for operation and maintenance turns out to be a disadvantage for the detection of the cage rotor bar and endring defects, which means that the detection of cage faults is due to the measurement and analysis of only the stator input signals. The monitoring task in an inverter drive is complicated mainly because the voltage and current waveforms are nonsinusoidal and the high dv/dt values from fast switching inverterd distort the measurements. in this paper, we are going to discuss the detection method of broken rotor bar of squirrel cage induction motor by the motor current signal analysis(MCSA).

Power electronic converters generate the harmonic voltage and current, and these harmonics have the harmful effects on the various components. For example, passive components such as capacitor and inductor, transformer, motor and other components are mainly affected in the power electronic system. Thus, the design and manufacturing of the power converters, which have the harmonic-free or mitigation strategies, are required. In particular, the lifetime and durability of these components are main requirement for enhancing the overall stability of the system. So, in this paper, the harmonics-related problems to the neighbouring components and mitigation research trends are presented.

In this paper, a communication system that is not using the communication line but power line is presented. It will be very useful for an information-oriented society with tole-metering and home automation. Conventional system has a difficulty in transmitting information due to decreasing communication voltage. Proposed idea is a special type switching amplifier system which has a low inner resistance and using high efficient ferrite core in a coupling circuit. This new system is proposed to overcome the loss of conductor load and coupling circuit in a PLC system.

In performing the three-level SVPWM, it is nearly impossible to control the neutral-point potential exactly to the half of the dc-link voltage at all times. Therefore the inverter would produce an erroneous output voltage by this voltage unbalance. So the voltage unbalance has to be compensated in doing PWM, when the voltage unbalance occurs whether it is small or large, to make the inverter output voltage follow the reference voltage exactly the same. In this paper, a new compensating method for the neutral-point potential variation in a three-level inverter space vector PWM (SVPWM) is presented. By using the proposed method, the output voltage of the inverter can be made same as the reference voltage and thus the current and torque ripple of the inverter driven motor can be greatly improved even if the voltage unbalance is quite large. The proposed method is verified experimentally with a 3-level IGBT inverter.

This paper proposes a modified $\alpha$ conduction mode for controlling the output voltage magnitude of three-phase square-wave VSIs with an R-L load. From the viewpoint of both power capacity and switching losses, three-phase square-wave inverters are now used in most high power systems. When the square-wave VSI is driven with $\alpha$ conduction mode to control the magnitude of output voltages, interval over than half period is operated with $180^{\circ}$ conduction mode and the other interval with $120^{\circ}$ conduction mode. In $120^{\circ}$ conduction mode operation, two output terminals are connected to DC supply and the third one remains open. The potential of this open terminal will depend on the load characteristics and is unpredictable except the case of pure resistive loads. To cope this problem, we propose the modified α conduction mode.

This Paper the state-of-the art indirect induction heated boiler and induction heated hot air producer using the voltage-fed series resonant high-frequency inverter whice can operate in the frequency range from 20kHz to 50kHz. A specially-designed induction heater composed of laminated stainless assembly with many tiny holes and interconnected spot welding points between stainless plates is inserted into the ceramic type vessel with external working coil connected to the inverter and tubelence fluid through this induction heater in moving fluid generates in the vessel. The operating performances of this unique appliance in next generation and its effectiveness are evaluated and discussed from a practical point of view.

Power Quality and Reliability are becoming important issues for critical and sensitive loads. This paper describes the Line Interactive UPS with the function of Voltage Compensator that is 'Line interactive Dynamic Voltage Restorer(LIDVR). The main purpose of a LIDVR is to compensate for voltage sag(dip), outage and overvoltage. The overall system consists of three controller 1) current controller with prediction 2) voltage controller and 3) proposed variable DC LINK controller. The variable DC LINK control technique using the LIDVR protects DC LINK from overflowing the input current. The simulation results are depicted in this paper to show the effect of this proposed system.

Compare with diode or thyristor bridge AC/DC converter, the 3 phase PWM converter has some merits of low THD and unit power factor. So, in many critical application like as UPS, using PWM converter is the trends. 3 phase PWM converter had been studied widely already. But analytical design procedure can not found from publication for hardware design and controller design. So, in this paper, 3 phase PWM converter analysis review was given. And from the DC analysis result, parameter design was done. From the AC model, the voltage controller and current controller was designed. The gain of controllers was calculated by analytical method.

There are two ways in the output voltage control method in PWM inverter. One is the double loop voltage control composed of inner current control loop and outer voltage control loop. Because it shows fast response and low steady state error, utilized in many application. The Other is single loop voltage control method composed of voltage control loop only. It's characteristics shows lower performance in case of high output impedance than double loop voltage control. But in low output impedance, it shows good control performance in all load range than double loop control. In this paper, single loop voltage control rule and gain was developed analytically, and these were verified through computer simulation and experiment.

The parallel operation system of UPS is used to increase reliability of power source at critical load. But parallel UPS system has a few defects, impedance is different from each other and circulating current occurs between UPSs, due to line impedance and parameter variation, though controlled by the same synchronization signal. According to such characteristic of parallel UPS, balanced load-sharing control is the most important technique in parallel UPS operation. In this paper, a novel power deviation compensation algorithm is proposed. it is composed of voltage controller to compensate power deviation that be calculated by using active and reactive current deviation between inverters on synchronous d-q reference frame.

A high power U.P.S system utilizing the parallel connection of low power U.P.S is developed. For the purpose of elimination the circular current between U.P.S.s, a digital circuit is employed. Furthermore a double phase synchronization and an interphase reactor are used to eliminate the circular current and the voltage ripples caused by the system parameter unbalances of parall connected U.P.S.s. The digital controller is implemented with ADSP21061 as aspect of a functional convenience.

In this paper, an application of asymmetrical duty control method to a boost input type active clamp DC-DC converter is discussed. In order to verify the discussed results, a 50W prototype converter is built and is tested. Through the experimental results an asymmetrical controlled boost input type active clamp converter is validated.

Most of inverters adopt a diode rectifier as an input stage, which has very simple and rugged structure and therefore low cost. In order to properly design the 3-phase diode rectifier with an output smoothing capacitor and input inductors, it is necessary to fully simulate the system due to its nonlinear characteristics. Therefore this paper describes the operating behaviors including the current commutation in detail by using the proposed equivalent circuit, and also proposes the Simulink-based model of the system. The simulation results show the validity of the proposed model in all operating conditions.

Recently, the demand of large capacity SMPS for industrial area is increasing. Full-bridge dc-dc converter with IGBT is most widely used for large capacity SMPS because IGBT has a low-conduction loss and large current capacity, But most large capacity Full-bridge do-dc converter using IGBT has low operating frequency because of switching loss at IGBT especially at turn-off by current tail and it's cause of relatively big converter size. MOSFET has low switching losses has been widely used for high frequency SMPS but it has a problem to apply to large capacity SMPS because it has large conduction resistance causing large on-time losses. In this paper, for reduction losses at switching device, MOSFET is applied at parallel with IGBT in full-bridge dc/dc converter.

A pulse frequency control(PFM) method for single-phase SEPIC-type rectifier is described in this paper. In the SEPIC rectifier, a relationship between the output power and the respective switching frequency is investigated to establish the control scheme of PFM. The propsed control method is provided with a feed-forward control loop of the output load as well as a feed-back control loop of the output voltage. The simulation results show good dynamic responses and unity power-factor operation.

Interleaved Dual Boost(IDB) converter can reduce current ripple, switching loss and harmonics without filter in input power line. Moreover, this improve power factor. In this paper, we will use the state average methode and small signal analysis at the Interleaved dual boost converter. 4-type controllers were designed by using control transfer function. The result of these controller simulations is analyzed and proposed a proper controller at IDB

This paper deals with the active clamp ZVS flyback converter for RF generator. The proposed converter has the characteristics of the low switching noise and high efficient regarding conventional flyback converter. To verify validity of the proposed converter, the 100kHz, 48V, 300W converter are simulation and experimental result. This converter will be apply to the discharge drive circuit for PDP(Plasma Display Panel) TV.

This paper analyzed PFC of active clamp ZVS flyback converter by adding two method PFC (Power Factor Correction) circuit - Two-Stage and Single-Stage. It improves on Flyback converter's disadvantage - loss increasing by switching, noise increasing, high voltage stress of switch - by adding active clamp circuit. Simulation results show to improve the input PF of 300W ZVS flyback converter by adding Single-Stage, Two-Stage PFC circuit.

A protection scheme for Unified Power Quality Conditioner (UPQC) is presented and analyzed in this paper. The proposed UPQC has the series active power filter operated as a high impedance k($\Omega$) to the fundamentals when short-circuit faults occur in the power distribution system, and three control strategies are proposed in this paper. The first is the method by detecting the fundamental source current through the p-q theory, the second is the method by detecting the fundamental component of load current in Synchronous Reference Frame(SRF) and the third is the method by detecting the input voltage. When the short-circuit fault occur in the power distribution system, the proposed scheme protects the UPQC without additional protection circuits. The validity of proposed protection scheme is investigated through simulation results.

A zero-voltage transition (ZVT) PWM boost PFC converter using a transformer to recover the resonant energy into the input voltage is proposed. The proposed converter reduces turn-off switching loss of the auxiliary switch. The resonant current of the auxiliary circuit is optimally reduced by the feed-forwarded input voltage. Moreover, the resonant energy of the auxiliary circuit is recovered into the load and input voltages. In this paper, the modes of converter operation are explained and analyzed, design guidelines are given, and experimental results of 1.2kW, 200kHz prototype system are presented.

This paper deal with the power factor improvement of DC power regenerating systems, which are composed of two inverters, zig-zag connected output transformers, and an AC filter. The output voltages of the inverter system are not sinusoidal. Regenerated complex power is analyzed on the basis of fundamental components and therefore the reactive power produced by harmonics is not considered. Therefore, it is needed a new control scheme capable of controlling the reactive power nearly to zero for nonsinusoidal case. Computer simulations are carried out to verify the validity of the proposed control scheme.

In this paper, we proposed AC/DC boost converter to improve input current harmonic reduction in SMAW(shielded metal-arc welding). The proposed harmonic reduction with the boost converter design and the UC2854 integrated circuit which controls the converter, The topology of welding power supply is made of a pair of boost converter and welder half-bridge IGBT inverter. The voltage arc is modeled by a variable resistance in series with a voltage source. The results has been confirmed by PSIM simulation tool. The simulation results show that input at current is nearly sinusoidal with low harmonic contents and sinusoidal input current waveform at high power factor.

본 연구에서는 3상 능동 직렬형 전압 보상기의 제어 알고리즘으로 공간 벡터 검출법(3-D SV)을 제안하고 있다. 제안된 3차원 공간 벡터법은 종전의 순시전력이론에 의한 방법에 비해 보상 기준치 연산과정을 간략화 할 수 있고 좌표변환이 필요치 않다. 제안된 알고리즘은 전원전압의 순간적인 sag가 발생되더라도 비선형 부하에 인가되는 전압은 일정한 정현파로 제어 가능하며 동시에 전원전류의 고조파와 기본파 무효전류도 보상 가능하다. 정상상태와 과도상태에서 전력전자전용 시뮬레이터인 PSIM에 의해 제안된 이론의 타당성을 입증하였다.

A novel control scheme compensating for source voltage unbalance and harmonic current for series active power filters is proposed, where the references for voltage unbalance and current harmonic and phase angle is derived from the positive sequence component of the source voltage obtained simply through digital all-pass filters, which makes the whole control algorithm simpler than other methods using p-q theory. In addition, the harmonic component of source current is compensated by harmonic component of load voltage and therefore fundamental component of source current is considered as separated terms for the control issue. The validity of the proposed scheme has been verified by experimental results.

The three-phase diode rectifier with capacitive Inter is highly sensitive to line voltage unbalance. Because of its inherent nonlinear characteristics small line voltage unbalance may cause highly unbalanced line current causing detrimental effects on power quality. This paper presents a theoretical basis on this 'unbalance amplification effect' and derives an analytical model of line current characteristics under unbalanced line voltage condition for various modes of operation. The results provide a basic and important guideline for optimal design of a three-phase diode rectifier with capacitive filter that is most commonly used for interfacing various power conversion equipments to power lines.

In this paper, the development of the LF power supply for dry scrubber is discussed. 1500kW, 100kHz LF power supply is designed and tested. The main power stage is used for the FB PWM inverter with an LC filter in the secondary circuit. The operation characteristics of LF power supply are verified by simulation and experimental results.

A high ignition voltage is required for the metal halide (MHD) lamp. In this paper, the ballast ignited by internal LC resonance of buck converter with minimum size is proposed. For minimizing the ignition current for device safety, the characteristic impedance is maximized. But this results In a large steady state ripple, which may cause the accoustic resonance. The steady state ripple cancellation network using the coupled inductor is proposed.

A conventional power supply to drive a microwave oven has ferro-resonant transformer and high voltage Capacitor(HVC). Though it is simple, transformer is bulky, heavy and has low-efficiency. To improve this defect a high frequency inverter type power supply has been investigated and developed in recent years. But, because of additional control circuit and switching device, inverter-type power supply is more expensive than conventional one. In this study, A new pulse power supply for Microwave Oven using novel HVC embedded high frequency transformer is proposed for down-sizing, cost reduction, and efficiency emprovement of Inverter type power supply. Also, equivalent circuit model is derived by impedance measurements. And the operation of proposed pulse power supply is verified by simulations and experimental results.

This paper presents a high frequency modulation electronic ballast for the metal halide lamp. As the proposed ballast operates in high frequency ranges (20kHz - 100kHz) and it can start up the lamp using the LC resonant circuit without external igniter, the proposed ballast is very compact. The proposed ballast is controlled with the modulated frequency in the range of 20kHz to 100kHz, and it has variable modulating frequencies between 200Hz and 2kHz in order to avoid the acoustic resonance phenomenon. In this paper, a new realtime acoustic resonance detection method is described and the experimental results with the proto-type ballast of 150W metal halide lamp with the dimming function are discussed.

A study of single-stage PFC electronic ballast with constant do-link voltage is presented in this paper. The proposed ballast is combined by two interleaved boost cells and a conventional half bridge dc/ac inverter, By exploiting the interleaving technique, the Input ripple current of the electronic ballast is reduced. Theoretical analysis and experimental results for two 45(W) fluorescent lamps are presented.

The method of supplying a single voltage source to a drive has a weak point that we can not determine whether discharging cells of a upper panel in a PDP(Plasma display panel) operate properly or not in the step of testing a durable voltage. From this paper, we can make more reliable products by the design-method of a power-module, for testing a durable voltage, that can determine if discharging cells in a upper pannel in a PDP have something wrong in variously supplied voltage sources.

본 논문은 새로운 타입의 중첩형 오존발생기를 제안하였다. 방전시 방전실 내의 과도한 방전전력은 온도상승을 가져온다. 이러한 열로 인해 오존분해반응이 생성되어 오존생성수율이 나빠진다. 제안한 전원장치는 잉여전력을 재충전하여 열의 발생을 억제하고 오존분해반응을 줄일 수 있음을 실험으로 검증하였다.

This paper is indicating the problems, which are the conduction loss on the high frequency transformer, the protection of rectification diode as the snubber loss and the stress of switching main devices, as be made high current and high speed in the phase-shift switching full-bridge DC-DC converter is used the power supply's main circuit of high capacity. In this paper, to improve those problems, it is proposed that is the resonant circuit auxiliary can be reduced conduction losses and stabilized output control. And, it is constructed prototype of the power supply as the result of computer simulations.

One of the frequently used relay in industry is SR relay The SR relay has roughly two kinds. Wenn the power is off, one can memorize the previous ?tate and the other can be set automatically to the initial setting position. Those relays are constructed mechanically, so that they have some disadvantages, such as electro magnetical and acoustic noise. Such problem can be easily solvedby using a microprocessor. In this contribution will show the opportunity, how easily the relay function with a microprocessor can be reconstructed. As an example the function of Impulse Set Reset Relay will be discussed.

In this paper, a solution of network management system for power plant was introduced. In conventional systems, power installations use serial communication or MODEM for Management. In this case, it has a weak point in distance and speed. To solve these problems, the manage system based on Ethernet was developed. In order to implement, SNMP which is standard NMS of LAN was adapted, agent board and manager program for SNMP were developed.

In this paper, an intelligent demand control system was introduced. This system is composed of demand controller, RTU, Power Line Modem and HMI program. The developed demand controller was capable of synchronizing with watthour meter recommended by KEPCO. To control distant loads, network function using powerline communication is implemented in RTU, with HMI program, the untrained users are able to operate system easily. Additionally using the Powerline, the cost and time of installation is saved. The system performance was proved In a several experiments.

The neon transformer consists of magnetic circuit and leakage transformer. Since the silicon steel plate is used build a core, the system is big and heavy. Thus it is difficult to install Neon Sign it is even very dangerous if the system experiences a damage when it is installed inside. To overcome these problems, power electronic circuits are applied. The Inverter type Neon transformer using MOSFET is designed and implemented. The experimental results are described.

The constant voltage transformer(CVT) is a voltage regulator that has a high reliability, a good short circuit characteristic, a high input power factor, and a relative immunity to lightning strike. Moreover, this has a good line regulation without a voltage feedback control. In this paper, the characteristics of CVT for the changes of input voltage and other circuit parameters are investigated.

This paper presents a PSPICE circuit model for the simulation of both static and dynamic characteristics of fluorescent lamps. The model can by utilized for an electric ballast simulation with continuous dimming and transient mode simulation such as step dimming Characteristics of a Rosen-type piezoelectric transformer were analyzed by combining an equivalent circuit with piezoelectric equations and the relation between the characteristics and the dimension of the PT was studied.

The proposed contactless charger employs a pair of neighboring printed circuit board windings as a contactless energy transfer device, thereby making it amenable to low-profile designs and suitable for applications to the portable telecommunication/computing electronics in which stringent requirements for height, space, and reliability have to be met. The performance of the proposed charger is confirmed with experiments on a prototype charger developed for cellular phones.

Connectorless power transmission and supply are the power transfer device revealed by resonant inverter or transformer using inductant device. Recently, on power supply have been going on frequently, so several power supply circuit forms are announced. But Compared with the circuit of previous paper, instead of the circuit composed of a simple sylinder Ferrit, I was manufacture in a sylinder that It was a double overlab to a sylinder and I was followed a double flux in inner flux path. Above all, for practicalization, supply circuit operation character analysis and development of controller should be preceded. According to this paper, power transmission and supply analyze characters and design control circuit like the analysis of general resonant inverter for power transmission. They compose the circuit to get sinusoid wave output voltage using pulse width modulation control mode. For Supply, output wave form through power track and power pick-up of magnetic inductance includes ripper component. So I intend to design the controller including filter and regulator, compare analyze theoretical result with real measurement value and then show you their practicality

본 논문에서는 전력전달 매체인 전력선을 이용하여 신뢰성 있는 통신환경을 구축하기 위해 필요한 전력선 통신 시스템에서의 임피던스, 잡음, 특성 등을 고찰했다. 이를 바탕으로 기존 네트워크에 사용 되어온 DS-SS(Direct sequence-Spread Spectrum) 기법을 전력선 통신에 적용하여 전력선통신 시스템을 구성하고 다중 액세스 기법인 CSMA를 적용하여 시스템 효율에 대한 성능 평가를 하였다.

전기자동차의 추진시스템의 경우 차량의 종류에 따라 제어기 변수의 변동이 많은 것이 특징이다. 따라서 다양한 차량의 종류에 대해 소스프로그램의 수정 없이 차량 시스템 튜닝작업이 용이하도록 제어프로그램을 구현하는 것이 중요하며 이런 목적에 맞는 제어파라미터의 선정이 중요하게 된다. 또한 전기자동차는 승객의 안전과 직결되기 때문에 시스템 fault 처리에 대한 중요성이 높다. 본 논문에서는 전기 자동차 추진시스템의 제어기의 소프트웨어 구현에 대해 논한다.

In recent the energy efficiency of a refrigerator has been restricted extremely. A compressor consumes a great portion of input power in a refrigerator. So it is necessary to develop a more efficient compressor in these days. The existing reciprocating compressor need to a crank shaft to convert the rotating motion to the straight motion and is not efficient. But the linear compressor using mechanic resonance is efficient but need a drive instead of a crank shaft to control a position accurately. However it is impossible to apply a stroke sensor practically because of the internal circumstance of compressor. In this paper, A new sensorless stroke control method using the current and voltage of linear compressor is proposed.

This research used triac that is semi-conductor that act to static contact to overcome happened shortcoming been using mechanical centrifugal force switch usually Detect starting current of single phase induction motor and decided moving time. Therefore, could improve life of switch semipermanently. Also, wish to reduced impact that electric motor suffers at the starting moment and do stable starting which there is no life improvement and noise of electric motor itself, arc.

In This paper describes on the development of detecting power using Microprocessor. The detecting power system is composed of main controller system and analyzing software. Re system detected voltage, current, temperature, leakage current md its saved in ROM. This system applies the 'AT89C52' to CPU and 'AM29F040B' used a memory to sue the data.

As the fuzzy control is applied to servo system the hardware implementation of the fuzzy information systems requires the high speed operations, short real time control and the small size systems. The aims of this study is to develop hardware of the fuzzy information systems to be apply to servo system. In this paper, we propose a calculation method of approximate reasoning for fuzzy control based on $\alpha$-level set decomposition of fuzzy sets by quantize $\alpha$-cuts. This method can be easily implemented with analog hardware. The influence of quantization levels of $\alpha$-cuts on output from fuzzy inference engine is investigated. It is concluded that 4 quantization levels give sufficient result for fuzzy control performance of do servo system. It examined useful with experiment for dc servo system.

전력선통신 변조방식 중 FSK(Frequency Shift Keying) 변조방식을 이용하여 컴퓨터와 RS232 케이블로 전력선모뎀과 연결하여 컴퓨터의 데이터신호를 전력라인으로 직접 송신할 수 있게 하였으며, 수신부에서 데이터신호를 검출하여 가전기기의 전원을 ON/OFF하였다.

Generally, previous converter is divided into two categories to get high power factor and good output regulation. These two categories can be combined a category with a main switch. These converter is called Single Stage PFC Converter. This approach has good electrical characteristics of high power factor and fast output voltage regulation. The cost and size are important factor to design the converter in low power system. Even single stage can reduce the size and cost, but this approach needs to have additional circuit like control, PWM circuit. To improve these demerits, Top switch is one of good choice In reduce and size in low power single stage converter. Because it has the ability of current limit, thermal protection, oscillator, control circuit as well as a main switch ability.

In this paper, the improved zero-voltage transition(ZVT) PWM boost converter using an inductor feedback technique is proposed. The improved circuit uses a low-voltage zener diode to reduce the turn-off witching loss of the auxiliary witch and EMI noise. Using this technique, soft-witching for the auxiliary switch is guaranted at wide line and load ranges and some of the energy circulating in the auxiliary circuit is fed to the load Since the active switches are turned on and off softly, the witching losses and EMI noise are reduced significantly and the higher efficiency of the system is achieved. In this paper, the modes of converter operation are explained and analyzed, design guidelines are given, and experimental results of 1kW, 100kHz prototype system are presented.

In this paper a soft switching ZVT power factor converter using active snubbers is designed to improve efficiency and reduce voltage spike and parastic ringing. The main switch achieves ZVT and the auxiliary switch performs with ZCS. A 2KW soft switching ZVT converter is designed with switching frequency 100kHz, output voltage 400VDC. Then the designed system is realized and experimental results shows that the measured efficiency and power factor were over $97.45\%$ and 0.997 respectively with an input current THD less than $3\%$.

This paper proposes a new induction heating system composed of a thyristor PWM rectifier with a resonant commutation circuit. The operation of proposed system as first analyzed by a theoretical approach with equivalent circuits. And its verification was performed by computer simulations with EMTP. The proposed system can provide a solution for the power factor problem of the existing high-power induction heating system, which uses the line-commutated thyristor bridge in rectifier side.

This paper proposes an SSSC based on multi-bridge inverters. The dynamic characteristic of the proposed SSSC was analyzed by EMTP simulation and a scaled handware model, assuming that the SSSC is inserted in the transmission line of the one-machine-infinite-bus power system. The proposed SSSC has 6 multi-bridge inverters per phase, which generates 13 pulses for each half period of power frequency. The proposed SSSC generates a quasi-simusoidal output voltage by 90 degree phase shift to the line current The proposed SSSC does not require the coupling transformer for voltage injection, and has a flexibility in operation voltage by increasing the number of series connection.

The conventional three-level high frequency phase-shifted dc/dc converter has a disadvantage that a circulating current flows through transformer and switching devices during the freewheeling interval. Due to this circulating current and RMS current stress, conduction losses of transformer and switching devices increases. To alleviate these problems, we propose an improved three-level Zero Voltage and Zero Current Switching (ZVZCS) dc/dc converter using a tapped inductor, a snubber capacitor and two snubber diodes attached at the secondary side of transformer. The proposed ZVZCS converter is verified on a 10 kW, 30kHz experimental prototype.

A optimal soft switching technique for A/DC full bridge converter is proposed. variable soft switching single stage AC/DC full bridge converter with unit power factor are presented in this paper. Using soft switching, we can reduce a switching losses. As a result, achieving good power factor and achieving a good efficiency. We search a optimal soft switching technique in this paper and to verify the theoretical analysis of the presented AC/DC full bridge converter, a design example is given with its Pspice and Psim simulation and experimental results.

Loss analyses of two soft switching techniques for two-transistor forward converters are presented. The sums of snubber conduction and capacitive turn-on losses for two transistors are calculated to compare the losses of two techniques. While the conventional soft switching technique shows the loss difference between two transistors, proposed soft switching technique shows equal as well as lower loss in two transistors.