• Journal of Electrical Engineering and Technology
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• 제3권2호
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• pp.224-234
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• 2008

Multi-phase machines can be used in variable speed drives. Their applications include electric ship propulsion, 'more-electric aircraft' and traction applications, electric vehicles, and hybrid electric vehicles. Multi-phase machines enable independent control of a few numbers of machines that are connected in series in a particular manner with their supply being fed from a single voltage source inverter(VSI). The idea was first implemented for a five-phase series-connected two-motor drive system, but is now applicable to any number of phases more than or equal to five-phase. The number of series-connected machines is a function of the phase number of VSI. Theoretical and simulation studies have already been reported for number of multi-phase multi-motor drive configurations of series-connection type. Variable speed induction motor drives without mechanical speed sensors at the motor shaft have the attractions of low cost and high reliability. To replace the sensor, information concerning the rotor speed is extracted from measured stator currents and voltages at motor terminals. Open-loop estimators or closed-loop observers are used for this purpose. They differ with respect to accuracy, robustness, and sensitivity against model parameter variations. This paper analyses operation of an MRAS estimator based sensorless control of a vector controlled series-connected two-motor five-phase drive system with current control in the stationary reference frame. Results, obtained with fixed-voltage, fixed-frequency supply, and hysteresis current control are presented for various operating conditions on the basis of simulation results. The purpose of this paper is to report the first ever simulation results on a sensorless control of a five-phase two-motor series-connected drive system. The operating principle is given followed by a description of the sensorless technique.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1489-1491
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• 2004

A guard lamp system has been installed at the PV positive center, located at Gwangju in Korea. Digital environment that is represented to internet is displacing business way of industry and business achievement way with the fast speed being giving great change on life whole, improve existence business process utilizing internet and Web connection technology, information superhighway to tradition industrialist manufacture and e-transformation's propulsion that wish to maximize productivity and administration efficiency is spread vigorously. In this paper, we wish to accomplish generation equipment's heighten stability and believability through remote monitoring and control of guard lamp system. This paper describes the design of the monitoring system for the sensing data and indirect controlling of the guard lamp system. Most of the conventional monitoring systems depend on the special hardware and software. The essential design of monitoring system is to provide the convenience for the user and the portability for the system. In order for the system to fulfill its requirements, it was designed using Labview GUI facility based on the Windows 2000 environment of IBM PC compatible and Add-oncard based on the TCP/IP Protocol. Advantage of the monitoring system are a personnel expenses curtailment effect, of the place restriction and unmanned system of the generationplants, etc..

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1298-1300
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• 2002

This paper suggested that the technical specification of tilting train EMU for speed up on existing lines. High speed strategy of existing lines are the modification of railway system which are made on cant, lengths of transition curves, the catenary system and train system. Tilting technology is more useful a strategy for speed increases on existing lines with low investment needed. We performed a feasibility study which is considered out real track conditions and designed propulsion and braking system of tilting EMU system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.18-21
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• 1996

This paper deals with experimentation on static test of linear induction motor for the propulsion system of UTM(Urban Transit Maglev). It is very important that vertical force zero effects to levitation field of maglev. Because it is continuous for air gap 11mm of levitated maglev vehicle. Then we found the slip frequency that the vertical force zero due to it is variable. Thus we had compared between simulation value and experiment value for lim by static test Jig.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1210-1211
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• 2011

The inherent drawback of iron-core type permanent magnet linear synchronous motor (PMLSM) is detent force that is dependent on several major factors such as PM length, slot clearance, and skewing. To minimize the detent force, this paper proposes a structure optimization using the combination computation of two dimensional (2-D) finite element analysis (FEA) and response surface methodology (RSM). The RSM, that is a collection of the statistical and mathematical techniques, is utilized to predict the global optimal solution based on the FEA calculated results of the detect forces for different combinations of factors. With the help of the combination computation the high capacity iron-core type PMLSM with more than 12000 N propulsion forces only contains less than 3 N detent forces.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1228-1229
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• 2011

A novel approach has been promoted for FNN ship controllers. An Electro-hydraulic governor has been widely adopted to the ship speed control of propulsion marine diesel engines for a long time, it was very difficult for Electro-hydraulic governor to regulate the speed of high power engine with long stroke at low speed and low load, because of the jiggling phenomena by rough fluctuation of rotating torque and the hunting phenomena by long dead time occurred in fuel combustion process in the engine cylinder. This paper provides an efficient way for improving control performance by FNN controller. An RBF neural network and GA optimization are employed in a fuzzy neural controller to deal with the nonlinearity, time varying and uncertain factors, the rule base and membership functions can be auto-adjusted by GA optimization. The parameters of neural network can be decreased by using union-rule configuration in the hidden layer of the network. The performance of controller is evaluated by the system simulation using simulink tools.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.245-247
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• 2004

고속철도는 수많은 하이테크 기술의 결정체이며, 이 중에서도 추진장치는 차량의 성능을 결정하는 매우 중요한 요소이다. 이러한 전장품들에 대한 다양한 성능을 평가하고 진단하기 위해 상시계측시스템을 구축하여 활용하고 있다. 이러한 계측장비들은 여러 전장품에 대한 계측 및 분석을 통한 시험평가와 동시에 완성차 시험이나 본선시운전 시험시에 발생할 수 있는 고장원인을 찾아내고 해결하는데 많은 도움을 주고 있다. 본 논문에서는 강시계측 시스템을 통해 추진장치에 대한 고장진단을 실시한 내용에 대하여 기술하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.194-199
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• 2003

The traction drive system for the urban transit Rubber-tire system is described in this paper. To control the magnitude and frequency of the output voltage of induction motor transiently, the vector control strategy is generally used. But in case of the traction drive system for the railway vehicle, it is difficult to use the vector control caused by the one-pulse mode in the high speed region. Therefore, this paper proposes the control strategy combined the vector control in the low speed region and the slip frequency control in the high speed region. And also, the overmodulation PWM method is discussed to make the change to the one-pulse mode softly. The performance of the Proposed traction drive system is verified by the MATLAB simulation results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.613_614
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• 2009

Electric power steering(EPS) has many attentions such as fuel consumption improvement, thus it has been widely adopted for automotive application in recent years. In the EPS system, torque vibrations are directly transferred through the steering wheel to the hands of the driver. Hence, the design of PM motors for the EPS should be performed in order to reduce torque ripples including cogging torque. In this paper, Surface mounted Permanent Magnet Synchronous Motor(SPMSM) is designed to reduce torque ripples and cogging torque at a same time for the EPS propulsion and the design results are verified with the experimental ones.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.104-106
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• 2007

This paper presents the characteristic analysis of linear synchronous motor (LSM) with short-primary stator for 550km/h class high-speed Maglev propulsion system. The analysis results confirm the design and performance of LSM drives