• 전기학회논문지
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• 제66권2호
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• pp.459-467
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• 2017

An urban railway power substation consists of three thyristor dual converters. Two converters are connected to up and down trolley line to supply the electric energy or feed the regenerative energy back to the distribution. When the two converters break down, the remaining converter is used in an emergency. One thyristor dual converter system (TDCS) manages the energy of two or three railway stations. If the TDCS fails, the trains stop operating. To solve the problem, this paper proposes the three parallel operation control algorithm of thyristor dual converter system using the emergency converter. The broken TDCS can be replaced by the emergency converter in other TDCS. The effectiveness of this proposed control is verified by simulation.

• 전력전자학회논문지
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• 제20권6호
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• pp.573-579
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• 2015

A control algorithm of thyristor dual converter power system is proposed in this study for a railway power substation. The thyristor dual converter can use regenerative power without an additional system using control algorithm. An autonomous voltage and mode change method is also proposed to provide uninterrupted power to the railway. A 10 kW reduced model of the thyristor dual converter power system is built and tested to verify the validity of the proposed control algorithm.

• 전기학회논문지
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• 제65권3호
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• pp.511-519
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• 2016

This paper is proposed control algorithm for the using thyristor of the parallel dual converter for Urban railway power supply in order to return the regenerative power generated by regenerative braking in urban railway train. Conventional control algorithm of Thyristor dual converter for urban railway power supply has voltage variation within a control range of hysteresis band. The purposed control algorithm of the parallel thyristor dual converter is to maintain a constant voltage without voltage variation in accordance with variable load through the Sequential mode change. And the control algorithm need calculating optimum initial firing angle to consider magnitude of the load current slope. For this purpose, Proposed algorithm for sequential conversion mode of the dual converter was verified by applying for the simulation.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.674-682
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• 2017

This paper presents an optimal initial firing angle control based on the energy consumption and regenerative energy of a parallel multi-pulse thyristor dual converter for urban railway power substations. To prevent short circuiting the thyristor dual converter, a hysteresis band for maintaining a zero-current discontinuous section (ZCDS) is essential during mode changes. During conversion from the ZCDS to forward or reverse mode, the DC trolley voltage can be stabilized by selecting the optimal initial firing angle without an overshoot and slow response. However, the optimal initial firing angle is different depending on the line impedance of each converter. Therefore, the control algorithm for tracking the optimal initial firing angle is proposed to eliminate the overshoot and slow response of DC trolley voltage. Simulations and experiments show that the proposed algorithm yields the fastest DC voltage control performance in the transient state by tracking the optimal firing angle.

• 전기학회논문지
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• 제66권9호
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• pp.1437-1443
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• 2017

Electric energy is consumed or regenerated according to an operation of electric rail cars in urban railway power substations. A thyristor dual converter system is used to deal with the electric energy. Since the AC input voltage of power substations is $22.9kV{\pm}10%$, the magnitude of the AC voltage fluctuates according to load conditions, so the secondary side voltage of the DDY transformer also fluctuates. In the thyristor dual converter, the response characteristics of the DC output voltage and the DC output current are changed based on an initial firing angle in the cross mode conversion between the forward mode and the reverse mode. Therefore, this paper proposes the initial firing angle tracking algorithm considering fluctuation of the AC input voltage. The effectiveness of the proposed algorithm is verified by a simulation compared with the conventional algorithm.

• 전력전자학회논문지
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• 제22권1호
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• pp.9-17
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• 2017

A parallel control algorithm of thyristor dual-converter power system for the DC power supply of railway is proposed. The circulating current and current imbalance generated during parallel operation can be limited to control the output voltage of each power system by using the proposed parallel control algorithm. The proposed control algorithm can also eliminate output current sensor to achieve the same output response without additional costs. The validity of the proposed algorithm is verified through simulation and experiment.

• 대한전기학회논문지
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• 제36권3호
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• pp.179-187
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• 1987

Dual converter using diode bridge and 6-thyristor is discussed and the characteristics of this converter depending on their switching mode is revealed. The switching modes of converter operation are identified on both ac and dc sides. The circuit has the ability to accept or deliver DC current without change of nominal DC voltage magnitude or polarity and has the capability not only to instantaneously change from motoring to generating and vice versa, but to operate cycloconverter.

• 전력전자학회논문지
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• 제7권4호
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• pp.332-338
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• 2002

토카막 장치의 초전도 코일에 사용되는 전원 공급장치는 초대형급(20kA) 직류 전원 공급기로서 빠른 전류제어 응답성과 매우 작은 정상상태 리플이 필수적이다. 특히 역전류 공급이 가능한 회생형 컨버터의 운전중 전류 방향이 바뀌는 순간에도 전류기준값을 잘 추종하는 것이 중요하다. 이러한 조건들을 만족시키기 위하여 입력측에 2중 출력($\Delta$, Y)를 갖는 변압기와 출력단에 상간변압기(interphase transformer, IPT)를 이용한 12펄스 싸이리스터 듀얼 컨버터를 설계, 제작하였다. 각 컨버터에서 출력되는 전류의 합이 부하전류 지령치를 따르도록 제어하는 동시에 차 전류의 평균값이 영이 되도록 함으로써 각 컨버터의 부하 분담율을 일정하게 하여 상간 변압기의 포화를 방지한다. 대전류 코일 전류 공급장치의 양방향 전류 제어 성능을 높이기 위하여 위상각 검출 및 게이팅 지연각 구현을 디지털화하고 컨버터 전류방향 정역절환시 초기 응답특성을 개선하는 방법을 제안하였다. 또한 시뮬레이션과 실부하 전류실험을 통해 제안된 제어기의 동작성능을 확인하였다.

• 전력전자학회논문지
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• 제14권5호
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• pp.379-386
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• 2009

ITER 핵융합 장치에 사용되는 Vertical Stabilization(VS) 컨버터는 4상한 운전 모드의 대용량 부하에 전력을 공급하기 위해서 4개의 직렬구조 12펄스 컨버터를 역병렬 연결하여 구성한다. 스위칭 소자로 싸이리스터를 사용하는 VS 컨버터는 정역 운전모드 변환과정에서 컨버터의 안전운전을 위해 Dead Time 구간을 필요로하며, 이 과정에서 유도성 부하에 영(Zero)전류 불연속 구간이 발생하는 단점이 있다. VS 컨버터의 출력 전류제어에 순환전류를 이용할 경우에는 빠른 정역 운전모드 변환이 가능하며, 부하에 발생하는 영전류 불연속 구간을 제거할 수 있다. 본 논문은 ITER VS 컨버터에서 출력전류의 정역 운전을 위해 순환전류를 이용하는 부하 전류제어 알고리즘을 제안하고, PSIM 시뮬레이션을 통해 결과를 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.87-88
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• 2014

The paper presents a novel phase locked loop(PLL) control method for robust three-phase thyristor dual converters under sag, notch, and phase loss conditions. This method is applied to three line to line voltages of grid to derive three phase angle errors from three separated single-phase PLLs. They can substitute for abnormal phase to guarantee the synchronization in the various grid fault conditions. The performance of novel PLL with moving average method is verified through simulations.