• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권2호
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• pp.83-88
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• 1999

Series connection of power semiconductor devices is selected in high voltage and high power applications. It is important to prevent the overvoltage from being induced across a device above ratings by the proper voltage balancing in the field of IGBT series connection. In addition, the overvoltage induced by a stray inductance has to be limited in the high power circuit. This paper proposes a new gate control scheme which can balance the voltage properly and limit the overshoot by controlling the slope of collector voltage under the turn-off transient in the series connected IGBTs. The proposed gate control scheme changes the slope of collector voltage by sensing the collector voltage and controlling the gate signal actively. The new series connected IGBT gate driver is made and its validity is verified by the experimental results for series connected IGBT circuit.

• 전기의세계
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• 제13권3호
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• pp.21-27
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• 1964

A method of triggering a series connected complementary transister flip-flop is described. Also measurements have been made for the operation region with respect to the input pulse variation. This circuit is compared with a Eccles-Jordan flip-flop when it used as a Nixie tube driver of a neon lamp driyer.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권4호
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• pp.282-290
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• 2000

In this paper, the charge control with the input voltage feedback is proposed for the input series-output series-output parallel connected converter configuration for the high speed train power system application. This control scheme accomplishes the output current sharing for the output-parallel connected modules as well as the input voltage sharing for the input series connected modules for all operating conditions including the transients. It also offers the robustness for the input voltage sharing control according to the component value mismatches among the modules. And this configuration enables the usage of MOSFET for a high voltage system allowing a higher switching frequency for lighter system weight and smaller size. The performance of the proposed scheme is verified through the experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.195-197
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• 1998

The large scale industry needs high voltage converters. Therefore series connection of power semiconductor devices is necessary. It is important to prevent a device induced the overvoltage above ratings by proper voltage balancing in the field of IGBT series connection. In addition, the overvoltage induced by a stray inductance has to be limited in the high power circuit. This paper proposes a new gate control scheme which can balance the voltage properly and limit the overshoot by control the slope of collector voltage under series connected IGBT turn-off transient. The propose gate control scheme limits the overvoltage by sensing the collector voltage and controlling the gate signal actively. The new series connected IGBT gate driver is made and its validity is verified by the experimental results for series connected IGBT circuit.

• 전력전자학회논문지
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• 제4권1호
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• pp.99-104
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• 1999

최근 산업이 대규모화함에 따라 고압 전력 변환 장치의 필요성이 증가하고 있고, 이에 따라 전력용 반도체 소자의 직렬 구동이 많이 이용되고 있다. 소자의 직렬 구동은 소자간에 적절한 전압 분배가 이루어져 개별 소자에 정격이상의 과전압이 인가되는 것을 방지하는 것이 큰 관건이다. 또한 고전압 회로에서는 부유 인덕턴스에 의한 소자의 과전압도 방지하여야 한다. 본 논문에서는 직렬 연결된 IGBT의 턴-오프 과도상태시 컬렉터 전압 기울기 조절로 안정된 전압 분배와 과전압을 방지하는 새로운 게이트 구동기법을 제안한다. 제안하는 게이트 구동기법은 컬렉터 전압을 검출하여 능동적으로 게이트 신호를 제어함으로써 과전압을 제한한다. 새로운 IGBT 게이트 구동회로를 제작하고 직렬 연결된 IGBT 회로에 적용하여 게이트 구동기법의 타당성을 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.201-205
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• 1998

In this paper, the charge control with the input voltage feed forward is proposed for the input series-output parallel connected converter configuration for high voltage power conversion applications. This control scheme accomplishes the output current sharing for the output-parallel connected modules as well as the input voltage sharing for the input-series connected modules for all operating conditions including the transients. It also offers the robustness for the component value mismatches among the modules.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.455-459
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• 1998

In this paper input Series-Output Parallel connected converter configuration for high voltage power conversion applications is proposed and a control method to solve the problems of Input Series-Output Paralles connected converter configuration is introduced. In this configuration snubber circuit or voltage balancing controller that is necessary for the series connection of switching devices is not needed. The effectiveness of this proposed configuration is verified by simulation.

• Journal of Power Electronics
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• 제10권4호
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• pp.388-395
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• 2010

An active boost converter for a single phase SRM using series-parallel connected capacitors is proposed in this paper. The proposed active boost converter has two diodes and one power switch with an anti-parallel diode and one additional boost capacitor. The additional boost capacitor could be series or parallel connected to the dc-link capacitor to produce proper excitation and demagnetization voltage. The proposed active boost converter can easily achieve a fast excitation and demagnetization from the capacitor connection. In this paper, series and parallel connected converters are reviewed, and the detailed operating modes as well as the voltage characteristics of the proposed converter are analyzed. The simulation and experimental results shows the effectiveness of the proposed active boost converter.

• 전력전자학회논문지
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• 제13권6호
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• pp.461-468
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• 2008

본 논문에서는 연료전지용 전력변환 장치에서 높은 승압비를 구현하기 위하여 절연형 풀브릿지 컨버터의 고주파 변압기 2차측을 직렬로 연결한 새로운 DC/DC 컨버터와 이에 적합한 가변 위상변위 스위칭 방식을 제안하였다. 제안된 컨버터는 기존 방식에 비해 정류부와 필터부의 일원화가 가능한 구조로 출력레벨의 증가를 위해 컨버터의 수를 증가 하더라도, 수동소자의 수를 대폭 줄일 수 있다. 제안된 직렬 방식의 컨버터의 출력전압은 기존의 일정위상변위 스위칭 방식으로는 극성이 반대로 되는 구간이 발생하므로, 제안된 전력변환기에 적합한 간단한 가변 위상 변위 스위칭 방식을 적용함으로써, 출력전압의 감소문제를 해결하였으며, 시뮬레이션과 실험을 통하여 제안된 방식의 타당성을 검증하였다.

• 전력전자학회논문지
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• 제21권1호
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• pp.88-93
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• 2016

LCL filters are widely used in high-order harmonics attenuation of output currents in grid-connected inverters. However, output currents of grid-connected inverters with LCL filters can become unstable because of the resonance of the filters. Given that the characteristics of output currents in inverters mostly depend on filter performance, the exact analysis of filters by considering parasitic components is necessary for both harmonics attenuation and current control. LCL filters have three or four parasitic components: the series and/or parallel resistance of the filter capacitor and the series resistance of the two filter inductors. Most studies on LCL filters have focused on the parasitic components of the filter capacitor. Although several studies have addressed the parasitic components of the filter inductor at the inverter side, no study has yet investigated the concurrent effects of series resistance in both filter inductors in detail. This paper analyzes LCL filters by considering series resistance in both filter inductors; it proposes an active damping method based on the virtual series resistance of LCL filters. The performance of the proposed active damping is then verified through both simulation and experiment using Hardware-in-the-Loop Simulator(HILS).