• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.237-243
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• 2012

In this paper, a magnetic analysis of SRM(Switched Reluctance Motor) using 3d finite element method considering end-coil effect is presented. SRM models with different stator pole shapes are taken into consideration for the analysis of magnetic characteristics. It is observed that a stator pole shape model having a pole shoe depth is the most suitable one for railway traction application because it gives an improved inductance and torque characteristic. For a speed control of SRM, the PI and sliding mode controllers are applied to designed SRM with magnetic characteristic data obtained from the magnetic analysis. The simulations are carried out using Matlab-Simulink and the control performance is analyzed. By employing the sliding mode controller, the transient response as well as the steady-state error are much improved under a load variation of railway resistance under operation.

• The Journal of Engineering Research
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• v.5 no.1
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• pp.119-133
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• 2004

The gain-clamped EDFA has been developed to eliminate the output power change of WDM surviving channels to occur with added or dropped channels, which degrades the performance of EDM optical network. It maintains the constant gain of surviving channels when WDM channels are added or dropped in a network amplifying node. In this paper, the bi-directionally pumped gain-clamped EDFA is implemented to compensate the change of the input power by a lasing. The results show that the alsing of a short wavelength and backward propagation is the optimal condition to minimize the transient response of surviving channels in terms of the overshoot and gain saturation sue to the inhomogeneous broadening effect.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.7 no.4
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• pp.34-41
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• 1993

The dc servo motor has been often used as the driver for a position control system, because the performance of the control is excellent on the speed and position control. When the unknown disturbance and/or the varying quantity of load is imposed on the position control system, the response of the system has the steady and/or the transient state error.The objective of this work is to demonstrate the principles, design methodologies and implementation of a servo controller for reducing the error in the position control system using the dc servo motor. The coefficients of a servo controller are computed by the pole placement.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.213-219
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• 2021

In this paper, an incremental twisting compensator is proposed for improving the performance of helicopter control and tested on an in-house full-scale helicopter simulator. The proposed compensator has a merit in that an incremental control input (a second-order sliding mode control input or so-called twisting control input) is simply added to improve the performance of helicopter control, while the original flight control structure remains untouched. The proposed control technique has been shown to improve the transient and steady-state response of the in-house helicopter simulator.

• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.213-214
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• 2018

본 논문에서는 전기자동차 온-보드 충전기용 단상 cycloconverter-type high frequency link 컨버터의 전력 제어성능과 동적 응답특성을 개선하기 위하여 예측전류제어 기법을 적용한다. 배터리를 충전 및 방전하기 위하여 전력계통에 연결되는 V2G 충전기는 전압 변동, 고조파 왜곡 등의 외란 발생에도 강인한 동적 응답 특성을 유지하여야 한다. 예측전류제어 기법이 적용된 제어기는 계통 외란이 존재하는 경우에도 전력 레퍼런스를 빠르게 추적하고 정확한 듀티를 생성할 수 있으므로 우수한 동적 및 과도 응답특성을 갖는다. 제안하는 제어기의 성능과 파라미터 변동에 대한 민감도는 PSIM 시뮬레이션을 이용하여 평가되며, 여러 계통외란 상태에서 PI 제어기와 비교된다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.3
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• pp.199-207
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• 2003

This paper is proposed new fuzzy controller for high performance of interior permanent magnet synchronous motor(IPMSM) drive. New fuzzy controller take out appropriate amounts of accumulated control input according to fuzzily described situations in addition to the incremental control input calculated by conventional direct fuzzy controller The structures of the proposed controller is motivated by the problems of direct fuzzy controller. The direct controller generally give inevitable overshoot when one tries to reduce rise time of response especially when a system of order higher than one is under consideration. The undesirable characteristics of the direct fuzzy controller are caused by integrating operation of the controller, even though the Integrator itself is introduced to overcome steady state error in response. Proposed controller fuzzily clear out integrated quantities acrording to situation. This paper attempts to provide a thorough comparative insight into the behavior of IPMSM drive with direct and new fuzzy speed controller. The validity of new fuzzy speed controller is confirmed by response results for IPMSM drive system.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.101-102
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• 2012

본 논문에서는 3상 승압형 정류기를 위한 슬라이딩모드 기반의 센서리스 직접전력제어방법을 제안한다. 공간벡터변조방식을 이용한 직접전력제어기법은 히스테리시스 제어기를 사용한 방법에 비해 스위칭 주파수가 일정하게 유지되어 시스템 안정성은 향상되지만, 응답속도가 떨어지는 단점이 있다. 제안하는 방법은 센서리스 기법을 이용하여 전압 센서를 제거하였고, 슬라이딩모드 제어기를 이용하여 시스템의 응답속도를 개선하였다. 3상 승압형 정류기의 시뮬레이션 결과를 통해 제안하는 제어기법의 타당성을 검증한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.6
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• pp.1116-1121
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• 2001

Phase shifter has been used as a means of power-flow control and for transient stability improvement in AC transmission system. Until now, phase shifters have been based on an injection transformer. Conventional phase shifters with tap changers require regular maintenance and allow only step-like control of the phase angle. This paper propose a three-phase phase shifter using PWM AC/AC converter, which can improve system response and control stability in the applications. This paper deals with the circuit topology, operating principle so that the features of the phase shifter will be shown through computer simulation, especially using PSIM software.

• Journal of Advanced Navigation Technology
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• v.20 no.3
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• pp.190-195
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• 2016

In this paper, Propose to prevent compressor surge and improve the transient response of the fuel flow control system of turbojet engine. Turbojet engine controller is designed by applying Fuzzy-PID control algorithm. To prevent any surge or a flame out event during the engine acceleration or deceleration, the Fuzzy-PID controller effectively controls the fuel flow input of the control system. Fuzzy-PID results are used as the fuel flow control inputs to prevent compressor surge and flame-out for turbo-jet engine and the controller is designed to converge to the desired speed quickly and safely. Using LabVIEW to perform computer simulations verified the performance of the proposed controller. Response characteristics pursuant to the gain were analyzed by simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.359-362
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• 2001

Phase shifter has been used as a means of power-flow control and for transient stability improvement in AC transmission system. Until now, phase shifters have been based on an injection transformer. Conventional phase shifters with tap changers require regular maintenance and allow only step-like control of the phase an81e. This paper propose a three-phase phase shifter using PWM AC/AC converter, which can improve system response and control stability in the applications. This paper deals with the circuit topology, operating principle so that the features of the phase shifter will be shown through computer simulation, especially using PSIM software.