• 전력전자학회논문지
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• 제9권3호
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• pp.267-274
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• 2004

본 논문에서는 새로운 온라인 데드타임 전향보상기법을 제안한다. 데드타임 효과(dead-time effect)로 인한 출력 전압 오차를 외란전압으로 간주하고 이를 추정하여 전향보상한다. 외란전압의 크기를 시간지연제어기법을 이용하여 추정하고, 추정된 값과 측정된 전류와 위치 정보로써 외란전압을 계산한다. 데드타임 효과를 보상하기 위해 계산된 외란전압은 전압지령에 전향된다. 제안된 방법은 DSP TMS320C31을 사용하여 디지털방식으로 영구자석 동기 전동기 구동 시스템에 적용이 된다. 제안된 방법의 효용성을 검증하기 위해 이 시스템에서 실험을 수행하였고 그 결과는 제안된 방법의 효과를 잘 보여주고 있다.

• 전력전자학회논문지
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• 제27권5호
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• pp.367-375
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• 2022

Generally, a proportional-resonant controller is used to eliminate steady-state errors during the voltage-current control of a double-conversion uninterruptible power supply (UPS) in a stationary reference frame. Additionally, the feed-forward control compensating for the load current, which can be considered a disturbance of the voltage controller, can be used to improve the disturbance rejection performance. However, during the parallel operation of UPSs, circulating current can occur between UPS modules when performing both feed-forward control and droop control because feed-forward control reduces the circulating current impedance. This study proposes a feed-forward compensation technique that considers the impedance of circulating current. An additional feed-forward compensation technique is developed to enhance the disturbance rejection performance. The validity of the proposed feed-forward compensation technique is verified by the experiment results of the parallel operation of a 500 W double-conversion UPS module.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 추계학술대회
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• pp.257-258
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• 2011

This paper describes a new method for the seamless operation mode transfer of a PCS with minimized voltage disturbance. The proposed method provides reduced STS turn off time after line fault and smooth mode change between current and voltage control of the PCS. The usefulness of the method is verified through simulations with the consideration of the time delay in detecting a line fault and SCR turn-off time.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.71-72
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• 2010

This paper deals with the SCR thyristor switching characteristics of a 3-phase voltage disturbance generator. The series transformers of the generator require bypass SCR thyristors to provide the source voltage to the output terminal in normal operating mode. The SCR thyristor switching characteristics is quite different according to the connection point to the series transformer. The switching characteristics is analysed and verified through simulation results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.532-533
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• 2010

This paper deals with the SCR thyristor switching characteristics of a 3-phase voltage disturbance generator. The series transformers of the generator require bypass SCR thyristors to provide the source voltage to the output terminal in normal operating mode. The SCR thyristor switching characteristics is quite different according to the connection point to the series transformer. The switching characteristics is analysed and verified through simulation results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.242-243
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• 2010

This paper investigates a power supply of medium voltage with enhanced ignition characteristics for plasma torch. Series resonant half-bridge topology is presented to be a suitable ignition circuitry. The ignition circuitry is integrated into the main power conversion system of a multi-phase staggered three-level dc-dc converter with a diode front-end rectifier. The plasma torch rated for 3MW, 2kA and having the physical size of 1m long is selected to be a high enthalpy source in waste disposal system. The steady-state and transient operations of plasma torch are simulated. The parameters of Cassie-Mary arc model are calculated based on 3D magneto-hydrodynamic simulations. Circuit simulation waveform shows that the ripple of arc current can be maintained within ${\pm}10%$ of its rated value under the existence of load disturbance. This power conversion configuration provides high enough ignition voltage around 5KA during ignition phase and high arc stability under the existence of arc disturbance noise resulting in a high-performance plasma torch system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.935-936
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• 2006

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

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.552-554
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• 2005

This paper deals with a simple structured voltage disturbance generator for power quality improving devices. The proposed generator can be applied to the performance test of custom power devices. Voltage sag, swell, outage, unbalance and phase jump after outage are provided by the generator. The improving phase jump operating principle of the generator is described and analysed. The usefulness of the generator is verified through simulation.

• 전기학회논문지
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• 제57권3호
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• pp.403-408
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• 2008

The gyroscope is the sensor for detecting the rotation in inertial reference frame and constitute the navigation system together an accelerometer. As the inertial reference equipment for attitude determination and control in the satellite, the mechanical gyroscope has been used but it bring the disturbance for mass unbalance so the disturbance give a bad influence to the observation satellite mission because the mechanical gyroscope has the rotation parts. During the launch. The mechanical gyroscope is weak in vibration, shock and has the defect of narrow operating temperature range so it need the special design in integration. Recently the low orbit observation satellite for seeking the high pointing accuracy of image camera payload accept the FOG(Fiber Optic Gyro) or RLG(Ring Laser Gyro) for the attitude determination and control. The Ring Laser Gyro makes use of the Sanac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. It need the 1000V DC to create the He-Ne plasma in discharge tube. In this paper, the design process of the High Voltage Power Supply for RLG(Ring Laser Gyroscope) is described. The specification for High Voltage Power Supply (HVPS) is proposed. Also, The analysis of flyback converter topology is explained. The Design for the HVPS is composed of the inverter circuit, feedback control circuit, high frequency switching transformer design and voltage doubler circuit.

• 전력전자학회논문지
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• 제10권1호
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• pp.102-107
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• 2005

본 논문에서는 새로운 방식의 전압 sag-swell 발생기를 제안하여 UPS(Uninterruptible Power Supply), DVR(Dynamic Voltage Restorer), DSTATCOM(Distribution Static Compensator), SSTS(Solid State Transfer Switch)등의 전력품질 개선장치들의 성능시험을 하는데 용이하도록 하였다. 제안한 방식에 대하여 단상과 3상의 경우 전압 sag, swell, outage, unbalance 발생원리 및 동작원리를 설명하였으며 시뮬레이션과 실험을 통하여 효용성을 입증하였다. 제안한 방식은 간단한 구조, 높은 신뢰도, 넓은 전압변동발생 범위, 간단한 제어 등의 장점 뿐 아니라 저렴한 비용으로 시스템을 구현할 수 있는 특징이 있으므로, 특히 실험실 레벨에서 효과적으로 경제적인 시스템을 구현하고자 하는 경우에 크게 기여할 것으로 기대한다.