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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Transactions of The Korean Institute of Electrical Engineers
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The Korean Institute of Electrical Engineers
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Volume & Issues
Volume 60, Issue 12 - Dec 2011
Volume 60, Issue 11 - Nov 2011
Volume 60, Issue 10 - Oct 2011
Volume 60, Issue 9 - Sep 2011
Volume 60, Issue 8 - Aug 2011
Volume 60, Issue 7 - Jul 2011
Volume 60, Issue 6 - Jun 2011
Volume 60, Issue 5 - May 2011
Volume 60, Issue 4 - Apr 2011
Volume 60, Issue 3 - Mar 2011
Volume 60, Issue 2 - Feb 2011
Volume 60, Issue 1 - Jan 2011
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IEC 61850 Application in Distribution Automation System
Kim, Taw-Wan ; Lim, Il-Hyung ; Choi, Myeon-Song ; Lee, Seung-Jae ; Kwon, Sung-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 687~693
DOI : 10.5370/KIEE.2011.60.4.687
In this paper, problems and solutions are proposed for applying IEC 61850 to Distribution Automation System(DAS). Communication protocol integration in power automation system have issued by IEC standards, IEC 61850 of them has researched for applying IEC 61850 to many areas of power system in spite of that it was made for substation automation system. Especially, DAS is just about to apply IEC 61850 by communication network change from serial to ethernet although DNP 3.0 is used. But it's impossible to apply directly IEC 61850 to DAS by difference of environment which unfixed wide area and separated nodes in power distribution system unlike concept of IEC 61850 is made by Substation Automation System(SAS) environment of limited space. Thus, this paper proposed applications of three types which conceptual, practical, and future to consider problems and solutions when apply IEC 61850 to Ethernet based DAS.
Comparison of Striking Distance Formulae and Their Effect on Lightning Shielding Analysis
Kim, Sung-Sam ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 694~699
DOI : 10.5370/KIEE.2011.60.4.694
This paper compares the performance of lightning shielding analysis methods using the seven striking distance formulae in substation. For comparison, we evaluate the number of expected strikes and exposed area using WinIGS Software. Seven striking distance formulae are compared using the electrogeometric model analysis and the rolling sphere method. Based on the electrogeometric model analysis, the risk of shielding failure in either the whole substation or parts of it is determined. According to the simulation results, one can justify whether the substation satisfies the criterion of shielding design. In particular, according to the rolling sphere method, the exposed areas in substation determine the location of the additional shielding poles or shield wires. Therefore, the installation of the additional shielding poles and shield wires in substation was accepted by shield design at the phase conductors exposed in the larger area.
A study result on coordinative protection method of HTS cable implemented distribution system
Lee, Hyun-Chul ; Yang, Byeong-Mo ; Lee, Geun-Joon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 700~704
DOI : 10.5370/KIEE.2011.60.4.700
This paper proposes a coordinative protection study results of 22.9kV HTS(High-Temperature Superconducting) cable implemented distribution system. HTS cable can provide about 5 times larger transfer capacability compare to conventional XLPE cable, however, it has different heat characteristic so called quench. This paper presents the simulation results on Ichun substation HTS cable which connects main transformer and 22.9kV bus. Various expected fault cases are considered and discussed to examine whether conventional protection scheme is effective to protect both of existing facilities and HTS cable. With the results of simulation, conventional protection scheme can be used if instantaneous element and time inverse elements could be adjusted with proper time coordination. Internal temperatures of HTS cable conductor in safe region with proper protection without quench. This results are to be demonstrated by the field test and will be implemented in Ichon substation HTS cable protection and control system.
Establishment of Generator Maintenance Scheduling Considering Minimization of CO
Oh, Tae-Gon ; Baek, Ung-Ki ; Choi, Jae-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 705~710
DOI : 10.5370/KIEE.2011.60.4.705
This paper proposes establishment of generator maintenance scheduling(GMS) considering minimization of
emissions. The objective function model to minimize
emissions is used in this paper. In this paper, and also, GMS is established due to freedom of GMS of generators owned by a designated generation company. The practicality and effectiveness of the proposed approach are demonstrated by simulation studies for a real size power system model in Korea in 2010.
Calculation of Generator Reactive Reserve Considering Network Configuration
Seo, Sang-Soo ; Kim, Dae-Jeong ; Choi, Yoon-Hyuk ; Lee, Byong-Jun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 711~716
DOI : 10.5370/KIEE.2011.60.4.711
This paper defines a generator reactive reserve considering power system network. Conventional generator reserve is calculated by the difference between the maximum reactive power output of generator and the current reactive power of generator. However, all generators could not affect on the whole power system. Thus, the effective generators should be selected by sensitivity analysis. The sensitivity depends on network configuration is the relation between generator reactive power outputs and reactive power loads. Using the sensitivity, the effective generator reactive reserve can be calculated.
Daily Unit Commitment Scheduling of Power System with Energy Storage System
Song, Ha-Na ; Jang, Se-Hwan ; Kim, Hyeong-Jung ; Roh, Jae-Hyung ; Park, Jong-Bae ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 717~725
DOI : 10.5370/KIEE.2011.60.4.717
In the power system with an electric storage system that can increase utilization rate of the source of such new renewable energy, this paper introduces the approach on the daily unit commitment scheduling that determines simultaneously optimum operational condition and output of thermal generators and electric storage device. The unit commitment is one of the most important issues in economic operation and security of short-term operational plan of the power system. It is to determine on/off status of generator to minimize operational cost during the given period. The committed generator should satisfy various operational limitation such as estimated demand by system, spinning reserve condition within minimum operational cost. In order to determine on/off or charge/discharge/idle condition and output level of units and electric storage system, the MILP(Mixed Integer Linear Programming) is suggested. The proposed approach is the mixed method between LP(Linear Programming) and IP(integer programming) which seeks the value of real number and integer that maximize or minimize function objective within given condition. The daily unit commitment problem with the electric storage system is applied to MILP algorithm through linearization and formulation process. The proposed approach is applied to the test system.
Study on the Estimation of Macroscopic Outage Cost using Reduction of Regional Added Value due to Power Outage
Lee, Jae-Gul ; Choy, Young-Do ; Jeon, Dong-Hoon ; Seo, Chul-Soo ; Choi, Jae-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 726~732
DOI : 10.5370/KIEE.2011.60.4.726
To establish the transmission system expansion plan based on reliability, valuation of outage cost become more important. In previous studies about outage cost estimation, macroscopic, microscopic and analytic methods are proposed but they have some limit. For instance, microscopic method involves a complex field survey process and macroscopic method can not estimate regional outage cost. So in this paper, a new method to estimate regional macroscopic outage cost using the reduction of value added due to power outages is proposed. This method uses regional add value according to production activities called Gross Regional Domestic Product(GRDP) and regional electricity sales.
Source Model for Harmonic Interaction Analysis between Renewable Energy Generators and Power Distribution System
Cho, Sung-Min ; Shin, Hee-Sang ; Moon, Won-Sik ; Kim, Jae-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 733~738
DOI : 10.5370/KIEE.2011.60.4.733
As increase of nonlinear loads and renewable energy generators (REGs) being connected to power distribution system via inverters, the concern on harmonic problems have increased. Recently, the harmonics evaluation method considering TDD (Total Demand Distortion) is used to analyze the effect of harmonics from inverters on power distribution quality. Harmonic current sources are typically used for simulation of nonlinear load. Most inverter type for REGs is voltage source inverter (VSI). So, harmonic voltage sources are more suitable to analyze impact of renewable energy generator on harmonics problem in power distribution system. In this paper, we presented the circuit model to analyze interaction between harmonics from nonlinear load and REGs. We verified that the harmonic analysis using the proposed circuit model is more appropriate than the harmonics evaluation method considering TDD through case study using PSCAD/EMTDC.
Performance Improvement of IPM-type BLDC Motor Using the Influx Method of Spatial Harmonic in Air-gap Flux Density
Lee, Kwang-Hyun ; Reu, Jin-Wook ; Hur, Jin ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 739~745
DOI : 10.5370/KIEE.2011.60.4.739
This paper proposes a method for reducing the negative spatial harmonics of the radial flux density of an interior-type permanent magnet (IPM) motor. The reliability of the motor is increased by minimizing its vibrations under dynamic eccentricity (DE) state and normal state due to reduction of a negative spatial harmonics component through the influx of a zero spatial harmonics component in the radial flux density. To minimize the vibrations, optimal notches corresponding to the distribution shape of the magnetic field are designed on the rotor pole face. The variations of vibration computation by finite element method (FEM) and the validity of the analysis and rotor shape design are confirmed by vibration and performance experiments.
Design and Analysis of Double Stator Type Bearingless Switched Reluctance Motor
Peng, Wei ; Lee, Dong-Hee ; Ahn, Jin-Woo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 746~752
DOI : 10.5370/KIEE.2011.60.4.746
In this paper, a novel bearingless switched reluctance motor (BLSRM) with double stator is proposed. This motor has two stators. Torque stator is outside, which mainly produces rotational torque. Radial force stator is inside, which mainly generates radial force to suspend the rotor. A novel structure and operating principle are presented. And characteristics of the proposed structure such as magnetic flux distribution, inductance, torque and radial force are analyzed through finite element method. From the analysis, the proposed BLSRM has linear characteristic of radial force and independence from torque current.
Magnetic Field and Electric Field Generated in an HTS Tape of a High Temperature Superconducting Magnet
Kim, Young-Min ; Ku, Myung-Hwan ; Cha, Guee-Soo ; Jeon, Chang-Wan ; Paik, Kyoung-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 753~758
DOI : 10.5370/KIEE.2011.60.4.753
Magnetic field and Electric field of High Temperature Superconducting magnet are very important to analysis of superconducting magnet. The maximum perpendicular magnetic field was applied to the outermost pancake windings. The critical current of all the magnet windings is limited by the critical current of the outermost pancake windings. The E-J relation was used to determine the critical current, and an evolution s trategy was adopted for the optimization of gap length between each pancake windins. The results of calculations show that the critical current and the central magnetic field and uniformity increased by 82.6% and 31.6% and 50.8%, respectively, for a magnet consisting of ten pancake windings. This paper did an analysis the cause of increase the critical current and central magnetic field and uniformity in no gap and optimal gap model.
Assistant Model For Considering Slot-Opening Effect on No-load Air-gap Flux Density Distribution in Interior-type Permanent Magnet Motor
Fang, Liang ; Kim, Do-Jin ; Hong, Jung-Pyo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 759~765
DOI : 10.5370/KIEE.2011.60.4.759
This paper proposes an effective assistant model for considering the stator slot-opening effect on air gap flux density distribution in conventional interior-type permanent magnet (IPM) motor. Different from the conventional slot-opening effect analysis in surface-type PM (SPM) motor, a composite effect of slot-opening uniquely existing in IPM motor, which additionally causes enhancement of air gap flux density due to magnet flux path distortion in iron core between the buried PM and rotor surface. This phenomenon is represented by a proposed assistant model, which simply deals with this additional effect by modifying magnetic pole-arc using an effective method. The validity of this proposed analytical model is applied to predict the air gap flux density distribution in an IPM motor model and confirmed by finite element method (FEM).
A Study on the Failure Analysis and Representation Test Method of High Frequency Transformer for SMPS
Lim, Hong-Woo ; Lee, Young-Joo ; Han, Ji-Hun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 766~770
DOI : 10.5370/KIEE.2011.60.4.766
In this paper, we describe the failure analysis and representation test method that applied high frequency transformer for SMPS through analysing insulation resistance, frequency characteristic, CT analysis, Q-factor atc. And we study the judgement method that a high frequency transformer affects to other beside parts in different condition or environment. According to this method, we devise a plan for the field failure prevent and propose the securing product reliability of high frequency transformer.
A Study on Design of Linear Induction Motor in Dynamic Tester for Catenary-current Collection
Ham, Sang-Hwan ; Cho, Su-Yeon ; Lee, Ju ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 771~775
DOI : 10.5370/KIEE.2011.60.4.771
This paper presents design process of linear induction motor in dynamic tester for catenary-current collection. To minimize length of rail for dynamic tester for catenary-current collection, accelerating performance of the linear induction motor is very important. So the design process of linear induction motor considered in this paper is different with general design process of linear induction motor, because dynamic tester has three type driving region, as accelerating region, constant speed region, and braking region. Considering accelerating performance of motor, distance and time from starting point to constant speed region were concerned for load condition of motor. Designed linear induction motor was analyzed by 2-dimensional finite element method. Using mechanical dynamics simulation with analysis result of 2-dimensional finite element method and accelerating performance of designed motor was proved.
A Study of Winding Design for Capacitor Run Single phase Induction Motor
Ham, Sang-Hwan ; Im, Jong-Bin ; Lee, Ju ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 776~780
DOI : 10.5370/KIEE.2011.60.4.776
This paper is concerned with winding design in capacitor-run single phase motor. Winding design in single phase induction motor is more complicated than that in three phase induction motor, because of using concentric winding in the single phase. Various winding designs are possible, and accordingly layout of the slot is calculated by formula. And then accurate design of winding is available. Using the design process in this paper, we can get the base model with slot layout and turns of windings of 1.12 kW single phase induction motor, and it is verified by finite element analysis. In this paper, winding design and winding layout of single-phase induction motor using concentric winding are suggested.
A Study on a Boost-Input Self-Driven Active Clamp ZVS Converter
Jin, Ho-Sang ; Kim, Hee-Jun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 781~788
DOI : 10.5370/KIEE.2011.60.4.781
This paper proposes a boost-input self-driven active clamp ZVS converter eliminating the extra dirve circuit for the active clamp switch. The converter used the auxiliary winding of the transformer to drive the active clamp switch and to achieve asymmetrical duty control. This paper presents the operation principle and the analyzed results of dynamic characteristics including steady state characteristics of the converter proposed. The experimental results were used to verify the theoretical predictions. A 300W (15V/20A) prototype converter that only exhibited 2-turn winding number in the auxiliary winding was sufficient to drive the active clamp switch on the input voltage of 80V. Finally, the maximum efficiency of 91.2% was achieved for the prototype converter and the proposed converter had stable closed loop characteristic with phase margin
Loss Calculation of a High Power DC-DC Converter Considering DC Bias Characteristic of Inductor
Jo, Young-Chang ; Choi, Ju-Yeop ; Jung, Seung-Ki ; Choy, Ick ; Song, Seung-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 789~795
DOI : 10.5370/KIEE.2011.60.4.789
It is necessary to accurately predict converter losses for optimized design of a high-power DC-DC converter. The losses of switching devices and inductor among the elements of the converter take significantly greater proportion. The current ripple will be determined by the size of the inductance and this inductance value varies depending on the DC amount of inductor current. As the inductance changes according to load current, the change influences not only the inductor loss itself but also the total converter loss. In this paper, for more accurate design of a bi-directional DC-DC converter for 30kW-class energy storage system, more accurate computational model is proposed considering inductance variation according to the load current change. The inductance changes using variable magnetic cores are verified and converter efficiency is tested through simulations and experiments.
A Sturdy on the Sleep Twist Round type Stacked Wind Power System for Appling Environment-Friendly Building and High Rise Housing
Jung, Ja-Choon ; Jang, Mi-Hye ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 796~800
DOI : 10.5370/KIEE.2011.60.4.796
As the increasing integrity of VLSI, the BIST(Built-In Self Test) is used as an effective method to test chips. Generally the pseudo-random test pattern generation is used for BIST. But it requires too many test patterns when there exist random resistant faults. Therefore we propose a mixed test scheme which applies to the circuit under test, a deterministic test sequence followed by a pseudo-random one. This scheme allows the maximum fault coverage detection to be achieved, furthermore the silicon area overhead of the mixed hardware generator can be reduced.
Electrical Properties of lead free (Na,K,Li)(Nb,Sb,Ta)O
Ceramics with MnO
Lee, Seung-Hwan ; Nam, Sung-Pill ; Lee, Dong-Hyun ; Lee, Sung-Gap ; Lee, Sang-Chul ; Lee, Young-Hie ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 801~804
DOI : 10.5370/KIEE.2011.60.4.801
Electrical properties and microstructure were investigated on the effects of
and the lead-free
ceramics with the addition of
were fabricated by a conventional mixed oxide method. A gradual change in the crystal and microstructure was observed with the increase of
addition. For the NKN-LST-xmol%
, bulk density increased with the addition of
and showed maximum value at addition 1.0mol% of
. Curie temperature of the NKN-LST ceramics slightly decreased with adding
. The dielectric constant, piezoelectric constant (
) and electromechanical coupling factor (
) increased below 0.25mol% of
addition, which might be due to the increase in density. The high piezoelectric properties = 145 pC/N, electromechanical coupling factor = 0.421 and dielectric constant = 2883 were obtained for the NKN-LST-0.25mol%
A Study on Estimation of Breakdown Location using UHF Sensors for Gas Insulated Transmission Lines
Park, Hung-Sok ; Han, Sang-Ok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 805~810
DOI : 10.5370/KIEE.2011.60.4.805
This paper deals with the method and algorithm used to find fault locations in gas insulated transmission line. The method uses UHF sensors and digital oscilloscope to detect discharge signals emitted to the outside through insulating spacer in the event of breakdown inside GIL. UHF sensors are the external type and installed at outside of insulating spacers of GIL. And we used wavelet signal processing to analyze the discharge signals and confirm the exact fault location findings in the GIL test line. This method can overcome demerit of TDR(Time Domain Reflectometer) method having been applied to detect fault location for conventional underground transmission lines, and Ground Fault Sensors used in conventional GIS systems. TDR method requires high level of specialty and experience in analyzing the measured signals. Ground fault sensors are installed inside GIL and can be destroyed by high transient voltage. This paper's method can simplify the fault location process and minimize the damage of sensors. In addition, this method can estimate the fault location only by the time difference when discharge signals are arrived to detecting sensors at the ends of GIL sections without reasons of breakdown. To test the performance of our method, we installed sensors at the ends of test line of GIL(84m) and sensed discharge signals occurred in GIL, energized with AC voltage generator up to 700kV.
An Optimal Design of a 19.05GHz High Gain 4X4 Array Antenna Using the Evolution Strategy
Kim, Koon-Tae ; Kwon, So-Hyun ; Ko, Jae-Hyeong ; Kim, Hyeong-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 811~816
DOI : 10.5370/KIEE.2011.60.4.811
In this paper, we propose a optimal design using the Evolution Strategy of a high gain
array antenna that have the resonant frequency of a 19.05GHz with 18.86GHz~19.26GHz bandwidth. The proposed array antenna structure is designed to be allocated equally electric power by microstrip patch power splitter. Thus the optimal array antenna with power splitter are determined by using an optimal design program based on the evolution strategy. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is constructed for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The simulation result of
array antenna is confirmed that the Gain is 19.36 dBi at resonance frequency 19.05GHz.
Applied of Integrated Optical Biosensor based on Combination of Photonic Crystal Micro-Cavity and Ring Resonator
Kim, Hong-Seung ; Kim, Doo-Gun ; Oh, Geum-Yoon ; Lee, Tae-Kyeong ; Choi, Young-Wan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 817~822
DOI : 10.5370/KIEE.2011.60.4.817
We propose a novel ring structure based on the stadium-shaped ring resonator (SSRR) with dual photonic crystal microcavity (DPCM) for biosensor and analyzed the sensing characteristics. The Q-factor of the photonic crystal microcavity (PCM) can be significantly enhanced when the PCM or DPCM has the same resonance condition as the SSRR. The simulation results show that the Q-factor of the SRR with DPCM was increased by three times in comparison with single PCM structure. We also defined a mutual interference between two PCMs. Assuming a detectable spectral resolution of 10 picometers, a refractive index resolution of
can be measured on the SSRR-DPCM.
Systematic Design and Realization of opto-electrical Predistortion Optical Transmitter based on Microwave Circuit Modeling for Radio-over-Fiber Systems
Lee, Tae-Kyeong ; Kim, Hong-Seung ; Oh, Guem-Yoon ; Kim, Doo-Gun ; Choi, Young-Wan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 823~828
DOI : 10.5370/KIEE.2011.60.4.823
We have systematically designed and experimentally demonstrated the opto-electrical predistortion optical transmitter using microwave circuit modelling for reducing the nonlinearity of the distributed-feedback laser diode (DFD-LD). The DFB-LD is analyzed using microwave circuits model based on rate equations. Through the system-level simulation for predistortion method, the optimized characteristics of the RF components in the system are confirmed. The simulated and experimental results show the reduced distortion products. These results are analyzed as the evaluation parameters for the miniaturization and optimization of the opto-electrical predistortion method in radio-over-fiber systems.
Development of Process Model for Turbine Control Valve Test in a Power Plant
Woo, Joo-Hee ; Choi, In-Kyu ; Park, Doo-Yong ; Kim, Jong-An ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 830~837
DOI : 10.5370/KIEE.2011.60.4.830
A turbine control system which has been operated for years in a nuclear power plant was retrofitted with a newly developed digital control system. After completion of the retrofit, turbine valve tests were performed to ensure the integrity of each valve's control function. The sequence of each valve test is composed of a closing process and a reopening process. To minimize megawatt variation which normally occurs during the test sequence, we employed a kind of compensator algorithm in the new digital control system which also have been used in the old system. There were difficulties finding optimal parameter settings for our new compensator algorithm because the power plant didn't allow us to perform necessary tuning procedures while the turbine is on load operation. Therefore an alternative measure for the compensator tuning which is independent of the turbine actual operation had to be implemented. So, a process model for the test was required to overcome this situation. We analyzed the operation data of the test and implemented the process model by use of input and output variable relations. Also we verified the process model by use of another condition's operating data. The result shows that the output of model is similar to the actual operation data.
Stable Adaptive On-line Neural Control for Wind Energy Conversion System
Park, Jang-Hyun ; Kim, Seong-Hwan ; Jang, Young-Hak ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 838~842
DOI : 10.5370/KIEE.2011.60.4.838
This paper proposes an online adaptive neuro-controller for a wind energy conversion system (WECS) that is a highly nonlinear system intrinsically. In real application, to obtain exact system parameters such as power coefficient, many measuring instruments and implementations are required, which is very difficult to perform. This shortcoming can be avoided by introducing neural network in the controller design in this paper. The proposed adaptive neural control scheme using radial-basis function network (RBFN) needs no system parameters to meet control objectives. Combining derivative estimator for wind velocity, the whole closed-loop system is shown to be stable in the sense of Lyapunov.
A Poof of Utkin's Theorem for the SI Uncertain Integral linear Case
Lee, Jung-Hoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 843~847
DOI : 10.5370/KIEE.2011.60.4.843
In this note, a proof of Utkin's theorem is presented for the SI(Single Input) uncertain integral linear case. The invariance theorem with respect to the two transformation methods so called the two diagonalization methods are proved clearly and comparatively for SI uncertain integral linear systems. With respect to the sliding surface transformation, the equation of the sliding mode, the sliding surface is invariant. Both the applied control inputs have the same gains. By means of the two transformation methods the same results can be obtained. Through an illustrative example and simulation study, the usefulness of the main results is verified.
Friction Compensation of the Pendubot based on the LuGre Model
Eom, Myung-Whan ; Kim, Cheol-Joong ; Chwa, Dong-Kyoung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 848~855
DOI : 10.5370/KIEE.2011.60.4.848
This paper proposes a method to reduce the limit cycle phenomenon that appears in the steady-state response of a pendubot system, when it is controlled by a state feedback controller based on the linearized system model. For this, we employed the compensator which estimates the friction based on the LuGre model in the LQR control. The proposed compensation method is validated by experiments for a pendubot system, which shows that the external disturbance as well can be efficiently compensated.
Formation Control of Mobile Robot for Moving Object Tracking
Oh, Young-Suk ; Lee, Chung-Ho ; Park, Jong-Hun ; Kim, Jin-Hwan ; Huh, Uk-Youl ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 856~861
DOI : 10.5370/KIEE.2011.60.4.856
The mobile robot controller is designed to track the target and to maintain the formation at the same time. Formation control is included in mobile robot controller by extending the trajectory tracking algorithm. The dynamic model of mobile robot is used with kinematic model considering the practical physical parameters of mobile robot. The dynamic model of mobile robot transforms velocity control input of kinematic model into torque control input which is the practical control input of mobile robot. Formation controller of mobile robot is designed to satisfy Lyapunov stability by backstepping method. The designed formation controller is applied to the mobile robot for various target movements and simulated to confirm the Lyapunov stability.
Evolutionary Design of Radial Basis Function-based Polynomial Neural Network with the aid of Information Granulation
Park, Ho-Sung ; Jin, Yong-Ha ; Oh, Sung-Kwun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 862~870
DOI : 10.5370/KIEE.2011.60.4.862
In this paper, we introduce a new topology of Radial Basis Function-based Polynomial Neural Networks (RPNN) that is based on a genetically optimized multi-layer perceptron with Radial Polynomial Neurons (RPNs). This study offers a comprehensive design methodology involving mechanisms of optimization algorithms, especially Fuzzy C-Means (FCM) clustering method and Particle Swarm Optimization (PSO) algorithms. In contrast to the typical architectures encountered in Polynomial Neural Networks (PNNs), our main objective is to develop a design strategy of RPNNs as follows : (a) The architecture of the proposed network consists of Radial Polynomial Neurons (RPNs). In here, the RPN is fully reflective of the structure encountered in numeric data which are granulated with the aid of Fuzzy C-Means (FCM) clustering method. The RPN dwells on the concepts of a collection of radial basis function and the function-based nonlinear (polynomial) processing. (b) The PSO-based design procedure being applied at each layer of RPNN leads to the selection of preferred nodes of the network (RPNs) whose local characteristics (such as the number of input variables, a collection of the specific subset of input variables, the order of the polynomial, and the number of clusters as well as a fuzzification coefficient in the FCM clustering) can be easily adjusted. The performance of the RPNN is quantified through the experimentation where we use a number of modeling benchmarks - NOx emission process data of gas turbine power plant and learning machine data(Automobile Miles Per Gallon Data) already experimented with in fuzzy or neurofuzzy modeling. A comparative analysis reveals that the proposed RPNN exhibits higher accuracy and superb predictive capability in comparison to some previous models available in the literature.
A Voltage-controlled Frequency Tunable CMOS Current-mode Filter for Software Radio
Bang, Jun-Ho ; Ryu, In-Ho ; Yu, Jae-Young ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 871~876
DOI : 10.5370/KIEE.2011.60.4.871
In this paper, a voltage-controlled frequency tunable current-mode integrator and a 3rd-order current-mode Chebyshev filter in 1.8V-
CMOS is realized for software radio applications in system-on-chips. This filter is used for reconstruction purposes between a current-steering DAC and a current-mode mixer. Power consumption of the designed filter can be reduced by using a current-mode small size integrator. And also, cutoff frequency of this filter is variable between 1.2MHz and 10.1MHz, the power consumption is 2.85mW. And the voltage bias compensated circuit is used to control the voltage variation.in the designed filter.
Estimation Algorithm of Bowel Motility Based on Regression Analysis of the Jitter and Shimmer of Bowel Sounds
Kim, Keo-Sik ; Seo, Jeong-Hwan ; Kim, Min-Ho ; Ryu, Sang-Hun ; Song, Chul-Gyu ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 877~879
DOI : 10.5370/KIEE.2011.60.4.877
Bowel sounds (BS) are produced by the movement of the intestinal contents in the lumen of the gastro-intestinal tract during peristalsis and thus, it can be used clinically as useful indicators of bowel motility. We devised an estimation algorithm of bowel motility based on the regression modeling of the jitter and shimmer of BS signals measured by auscultation. Ten healthy males (
years) were examined. Consequently, the correlation coefficient, coefficient of determination and standard error between the colon transit times (CTT) measured by a conventional radiograph and the values estimated by our algorithm were 0.98, 0.96 and 2.86, respectively. Also, through k-fold cross validation, the average value of the absolute differences between them was
hours. This method could be used as a complementary tool for the non-invasive measurement of bowel motility.
Dependence of External Magnetic Field in the Matrix-Type SFCL with the Separated or the Integrated Reactors
Cho, Yong-Sun ; Choi, Hyo-Sang ; Jung, Byoung-Ik ; Go, Sung-Pil ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 880~884
DOI : 10.5370/KIEE.2011.60.4.880
The matrix-type superconducting fault current limiter (MSFCL) consists of the trigger and current-limiting parts. The trigger part with reactors connected in parallel improves the quenching characteristics by applying the external magnetic field into the superconducting units. The current-limiting part with superconducting units connected in parallel and shunt reactors connected in series limit the fault current when the fault occurs. We developed the integrated reactor with the trigger and the current-limiting parts to apply high external magnetic field into the superconducting units. This was composed of a superconducting unit for the trigger part and two superconducting units for the current-limiting parts. We confirmed that the external magnetic field generated in the MSFCL with an integrated reactor was larger than that of the MSFCL with the separated reactors. So the differences of voltages generated between superconducting units were decreased in the difference according to the increment of the applied voltage. The whole magnitude of the SFCL was reduced because the volume of an integrated reactor could be reduced by one-third than that of the separated reactors. We confirmed that the critical behavior between the superconducting units in the MSFCL with an integrated reactor was more improved than that of the MSFCL with the separated reactors.
DC Leakage Current Properties Analysis of the LED Lamps of Road and Landscape Lighting
Kim, Hyang-Kon ; Kim, Dong-Woo ; Choi, Hyo-Sang ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 885~891
DOI : 10.5370/KIEE.2011.60.4.885
In this paper, we studied dc leakage current properties analysis of LED lamps of road and landscape lighting when leakage current appeared in dc power line. Generally, converter of LED lighting is divides to insulated type and non-insulated type according to components. When electric leakage happened in AC power line, earth leakage breaker(ELB) senses leakage current and interrupts electric circuit. In dc power source, We need experimental verification about dc electric leakage for electricity safety. In normal wiring conditions and in the water, in case of using insulated type of converter, dc leakage current did not occur. However, in case of using non-insulated type of converter, dc leakage current occurred and passed through into the ground. We found that there is a hazard of electric shock by dc leakage current. We expect that the results of these studies would be helpful for electrical safety of LED lamps for road and landscape lighting.
A Study on the Real Time Measuring Technique of Stray Current by Using Return Current Ratio in the DC Railway System
Jung, Ho-Sung ; Park, Young ; Kim, Hyeng-Chul ; Min, Myung-Hwan ; Shin, Myong-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 892~898
DOI : 10.5370/KIEE.2011.60.4.892
In DC electric railways, while an electric rail car is driving, a part of the working current returned to the substation through rails leaks into the ground. Such a stray current causes railway facilities and metal objects to corrode electrolytically. Therefore, change of stray current needs to be monitored constantly. But so far in domestic, the research on stray current measuring techniques and system adaption are insufficient. To estimate stray current, this paper addresses a method of monitoring the return current that is returned into the negative pole of the substation in real time.
Comparison of UV images and Measurement of the Corona Discharge from Insulators using the UV Sensor
Kim, Young-Seok ; Choi, Myeong-Il ; Kim, Chong-Min ; Bang, Sun-Bae ; Shong, Kil-Mok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 60, issue 4, 2011, Pages 899~904
DOI : 10.5370/KIEE.2011.60.4.899
Inspections and diagnoses of corona discharge are important in order to prevent electrical faults of external insulation in power systems. This paper studies a measurement of ultra-violet rays(UV) strength of corona discharges on insulators using a UV sensor with an optic lens. The data has been compared with the images of a UV camera. The UV sensor estimated that DC voltage needed to be set at 700V for accurate data analysis of the properties of UV detected during corona discharge. UV was generated at 60kV when the corona discharge occurred. UV strength and images of UV increased at a high voltage. The image area of the UV using a UV camera and the detection of UV using a UV sensor have shown, that the polymer insulator mounted on a live part must be checked when the applied voltage on the good polymer insulator is greater than 37.5% of its breakdown voltage.