• Journal of Power Electronics
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• 제4권3호
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• pp.138-151
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• 2004

In this paper, a constant frequency phase shifting PWM-controlled voltage source full bridge-type series load resonant high-frequency inverter using the $4^{th}$ generation IGBT power modules is presented for innovative consumer electromagnetic induction heating applications, such as a hot water producer, steamer and super heated steamer. The bridge arm side link passive capacitive snubbers in parallel with each power semiconductor device and AC load side linked active edge inductive snubber-assisted series load resonant tank soft switching inverter with a constant frequency phase shifted PWM control scheme is evaluated and discussed on the basis of the simulation and experimental results. It is proved from a practical point of view that the series load resonant and edge resonant hybrid high-frequency inverter topology, what is called, DE class type, including the variable-power variable-frequency regulation function can expand zero voltage soft switching commutation area even under low output power setting ranges, which is more suitable and acceptable for newly developed induction heated dual pack fluid heaters. Furthermore, even the lower output power regulation mode of this high-frequency load resonant tank inverter circuit is verified so that this inverter can achieve ZVS with the aid of the single auxiliary inductor snubber.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2000년도 학술대회논문집
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• pp.188-192
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• 2000

This paper presents a novel prototype of soft-switching PWM Full-bridge converter which incorporates active power switches in series with each rectifier diode in transformer secondary side. Switching and conduction losses of all the switches and devices are reduced as well as commutating current and circulating current flowing through transformer as compared with conventional converter. And duty ratio of primary switches is constant for maximum voltage conversion ratio. But this converter can be varied output by duty ratio of secondary switches. Operation principles basically the same as that of the PWM Full-bridge converter published previously. The operating characteristics of this converter are illustrate and discussed including the simulated analysis.

• 전력전자학회논문지
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• 제10권5호
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• pp.443-449
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• 2005

본 논문에서는 연료 전지 시스템을 위한 Z-소스 인버터로 구성된 병렬 운전 시스템을 제시 하였다. PWM 방식으로는 Carrier phase shifted SPWM을 적용하였으며 이 방식은 출력 전류의 고조파 성분을 줄일 수 있는 장점을 갖는다. 그러나 이 기법을 Z-소스 인버터로 구성된 병렬 운전 시스템에 적용하는 경우 추가적으로 순환 전류를 발생한다. Z-소스 인버터로 구성된 병렬 운전 시스템이 동작 시 발생하는 순환 전류를 분석하고 순환 전류를 감소시키며, 부하전류에 낮은 고조파 성분을 가질 수 있도록 순환 전류 리액터를 사용하였다. 이에 대한 적합성을 시뮬레이션과 실험을 통해 입증하였다.

• Journal of Power Electronics
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• 제16권2호
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• pp.512-521
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• 2016

Cascaded H-bridge multilevel (CHBML) inverters usually include a large number of isolated dc-voltage sources. Some faults in the dc-voltage sources result in unequal cell dc voltages. Unfortunately, the conventional phase-shifted carrier (PSC) PWM method that is widely used for CHBML inverters cannot eliminate low frequency sideband harmonics when the cell dc voltages are not equal. This paper analyzes the principle of sideband harmonic elimination, and proposes an improved PSCPWM that can eliminate low frequency sideband harmonics under the condition of unequal dc voltages. In order to calculate the carrier phases, it is necessary to solve transcendental equations for low frequency sideband harmonic elimination. Therefore, an approach based on the artificial bee colony (ABC) algorithm is presented in this paper. The proposed PSCPWM method enhances the reliability of CHBML inverters. The proposed PSCPWM is not limited to CHBML inverters. It can also be applied to other types of multilevel inverters. Simulation and experimental result obtained from a prototype CHBML inverter verify the theoretical analysis and the achievements made in this paper.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.231-234
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• 2003

This paper presents a novel high frequency transformer linked full-bridge type soft-switching phase-shift PWM control scheme DC-DC power converter, which can be used as power conditioner fur small-scale fuel cell power generation system. Using full-bridge soft-switching DC-DC converter topology makes possible to use low voltage high performance MOSFETs to achieve high efficiency of the power conditioner. A tapped inductor filter is implemented in the proposed soft-switching converter topology to achieve soft-switching PWM constant high frequency operation for a wide load variation range. to minimize circulating and idling currents without using additional resonant circuit and auxiliary power switching devices. The practical effectiveness of the proposed soft-switching DC-DC converter is verified in laboratory level experiment with 1 kW 100kHz breadboard setup using power MOSFETs. Actual efficiency of 94-96$\%$ is obtained for the wide load range

• Journal of Power Electronics
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• 제18권4호
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• pp.1140-1153
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• 2018

The harmonic impedance characteristic of a traction power supply system (TPSS) is necessary for taking actions to suppress the high-order harmonic resonances caused by AC electric locomotives. This paper proposes a controllable harmonic generating method (CHGM) for measuring the TPSS harmonic impedance by injecting harmonic disturbances of different frequencies and amplitudes into the TPSS. This method applies phase shifted pulse-width modulation (PSPWM) and ensures that the undesired sideband harmonics can be negligible while the desired harmonic is both controllable and adjustable. Multiple harmonics can be emitted at the same time. The implementation of the method is also presented. Simulations are carried out to validate the performance of the proposed method. Finally, experimental results on a 5 H-bridge converters platform verified the effectiveness and feasibility of the proposed method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.189-192
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• 2001

A new phase-shifted parallel-input/series-output dual converter for high-power step-up applications has been proposed. It features a high efficiency due to the low switch turn-off voltage, low device stresses, low ripple contents, and a fast control-to-output dynamics compared to its PWM counterpart. To confirm the validity of the proposed converter, experimental results from an 800W, 350Vdc prototype are presented.

• 전력전자학회논문지
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• 제5권3호
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• pp.209-214
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• 2000

본 논문에서는 FB ZVT PWM DC-DC 컨버터에서 영전압 스위칭에 도달하기 위해 두 개의 보조 스위치 대신에 가포화 인덕터를 사용한다. 기존의 고주파 위상 변위 FB ZVT PWM DC-DC 컨버터는 프리휠링 주기동안 고주파 변압기와 스위칭 소자를 통해 흐르는 순환전류를 갖으며, 이러한 순환전류로 인해 컨버터의 도전손실이 증가한다. 이러한 손실을 줄이기 위해 변압기의 2차측에 도전손실저감회로를 제안한다. 컨버터의 동작원리를 자세하게 설명하고 제안된 회로를 시뮬레이션과 실험을 통해 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.102-104
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• 2018

기존 위상 변조 PWM 풀 브릿지 컨버터들의 단점인 큰 순환전류, 심각한 이차측 전압 스트레스 및 스위칭 손실, 그리고 큰 출력 필터 문제를 개선할 수 있는 컨버터를 제안한다. 제안하는 컨버터는 변압기의 2차측 센터탭에 축전기와 정류기로 구성된 클램핑 회로를 연결한 구조이다. 매우 간단한 구조를 통해 순환전류를 제거하고 이차측 전압 스트레스를 낮출 수 있으며, 정류단의 스위칭 손실을 줄인다. 더불어 출력 필터의 크기 또한 작아진다. 실험을 통해 제안한 컨버터의 성능을 검증하였다.

• 조명전기설비학회논문지
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• 제20권4호
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• pp.21-28
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• 2006

본 논문에서는 Ballard사의 1.2[kW]급 연료전지와 연료전지의 저전압($28{\sim}43[VDC]$)을 승압(380([VDC])시키기 위한 풀-브리지 직류-직류 컨버터, 그리고 승압된 직류 링크전압을 교류 전압(220[VAC]), 60[Hz]으로 변환하기 위한 단상 풀-브리지 인버터로 구성된 연료전지 발전용 전력변환시스템 중 풀-브리지 고주파 절연형 영전압 영전류 스위칭 위상 천이 펄스폭 변조 직류-직류 컨버터를 제안하였다. 제안한 풀-브리지 고주파 절연형 영전압 영전류 스위칭 위상 천이 펄스폭 변조 직류-직류는 프리휠링 다이오드를 포함한 탭부 인덕터 필터를 이용하여 순환 전류를 저감시켰으며, 스위치 및 변압기의 턴-온, 턴-오프시에 오버슈트 전압이나 과도현상이 발생하지 않는다. 그리고 넓은 출력 전압 조정에도 효율을 $93{\sim}97[%]$정도 얻을 수 있으며, 출력 부하전류의 변화에 대해 거의 일정한 출력 전압 특성을 가졌다.