• 전력전자학회논문지
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• 제24권5호
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• pp.372-378
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• 2019

This study proposes a new zero-current-zero-voltage-transition (ZCZVT) boost-flyback converter using a soft switching auxiliary circuit. The proposed converter integrates the boost and flyback converters to increase the voltage with a low duty ratio. The main and auxiliary switches turn the ZCZVT conditions on and off. Thus, the proposed converter has high efficiency. The voltage gain at the steady state is derived, and the inductor volt-second balance and the design guidelines are presented. Finally, the performance of the proposed converter is validated by experimental results from a 200 W, 30 V DC input, 400 V DC output, and 200 kHz boost-flyback converter prototype.

• Journal of Power Electronics
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• 제19권2호
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• pp.549-559
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• 2019

This paper proposes an adaptive sliding mode control (ASMC) strategy with an enhanced optimal reaching law (EORL) for the robust current tracking control of the boost converter based hybrid power source (HPS) in an electric vehicle (EV). A conventional ASMC strategy based on state observers and the hysteresis control method is used to realize the current tracking control for the boost converter based HPS. Then a novel enhanced exponential reaching law is proposed to improve the ASMC. Moreover, an enhanced exponential reaching law is optimized by particle swarm optimization. Finally, the adaptive control factor is redesigned based on the EORL. Simulations and experiments are established to validate the ASMC strategy with the EORL. Results show that the ASMC strategy with the EORL has an excellent current tracking control effect for the boost converter based HPS. When compared with the conventional ASMC strategy, the convergence time of the ASMC strategy with the EORL can be effectively improved. In EV applications, the ASMC strategy with the EORL can achieve robust current tracking control of the boost converter based HPS. It can guarantee the active and stable power distribution for boost converter based HPS.

• 조명전기설비학회논문지
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• 제26권3호
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• pp.31-39
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• 2012

This paper presents a high efficiency coupled inductor boost DC-DC converter that uses a simple clamp circuit and the coupled inductor and thus overcomes output voltage limit of the conventional boost converter. The proposed converter solves problems of voltage stress of the power semiconductor switch and reverse recovery of the output diode using a simple clamp circuit composed of a diode and a capacitor, and thus the converter improves its total efficiency. In this paper, the operational principle of the proposed converter is explained by each mode and then a design example for the prototype converter based on the explanation is shown. And good performance of the proposed converter is verified through experimental results of the prototype converter that is implemented with the designed circuit parameters.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1428-1431
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• 2005

This paper presents an improved ZVT(Zero Voltage Transition) DC/DC Boost Converter using Active Snubber. The Conventional ZVT PWM Boost Converter is improved to minimize the switching loss of auxiliary switch using the minimum number of the components. In this thesis, advantage and disadvantages of Conventional ZVT Converter using a auxiliary resonant circuit is discussed. Then Improved ZVT soft switching converter will be discussed. In comparison a previous ZVT converter, the proposed converter reduces turn-off switching loss of the auxiliary switch. Therefore, the proposed converter has a high efficiency by active snubber. To show the superiority of this converter is verified through the experiment with a 640W, 100kHz prototype converter.

• 전력전자학회논문지
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• 제8권3호
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• pp.274-284
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• 2003

대용량 전력변환기기인 멀티-레벨 컨버터는 전동기구동시스템 및 유연송전시스템 등에 널리 사용되고 있다. 이중 H-Bridge 컨버터는 캐스캐이드 형태를 사용하여 멀티-레벨로의 확장이 용이한 장점으로 인해 shunt형 기기로 점차 응용이 확대되고 있다. 정상 상태에서 대략 0.7∼0.8의 변조지수 범위에서 작동한다. 고변조지수에서는 부스트 벡터인 zero vector가 인가되지 않아도 DC-link 전압은 일정하게 유지된다. 이것은 3-레벨 컨버터의 여러 벡터 중 zero vector 이외에도 또 다른 boost vector가 존재한다는 것을 의미한다. 본 논문은 boost vector의 원리를 살펴보고 3레벨 컨버터에서 zero vector와 또 다른 boost vector와의 차이점을 고찰하였다. 또한 본 논문은 두 토폴로지의 충전 전류와 커패시터 전압을 해석하고 비교한다 이 전압과 전류는 스위칭 상태와 기준전압과 관련되어 있고 이것을 이용하여 각 커패시터의 충전전류와 전압리플에 대한 계산 방법을 제안하였고 다양한 DC-Link 전압제어 방법을 시뮬레이션을 통해 비교하였다.

• 전력전자학회논문지
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• 제19권2호
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• pp.157-163
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• 2014

This paper proposes a two-stage step-down buck and a tapped-inductor boost cascaded converter for high efficiency photovoltaic micro-inverter applications. The proposed inverter is a new structure to inject a rectified sinusoidal current into a low-frequency switching inverter for single-phase grid with unity power factor. To build a rectified-waveform of the output current. the converter employs both of a high efficiency step-up and a step-down converter in cascade. In step-down mode, tapped inductor(TI) boost converter stops and the buck converter operates alone. In boost mode, the TI converter operates with the halt of buck operation. The converter provides a rectified current to low frequency inverter, then the inverter converts the current into a unity power-factor sinusoidal waveform. By applying a TI, the converter can decrease the turn-on ratios of the main switch in TI boost converter even with an extreme step-up operation. The performance validation of the proposed design is confirmed by an experimental results of a 120W hardware prototype.

• 한국산업융합학회 논문집
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• 제20권2호
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• pp.97-104
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• 2017

In the present industrial field, the demand for the development of the solar power source device and the charging device for the solar cell is gradually increasing. The solar charger is largely divided into a DC-DC converter that converts the voltage generated from the sunlight to a charging voltage, and a battery and a charger that are charged with an actual battery. The conventional charger topology is used either as a Buck converter or a Boost converter alone, which has the disadvantage that the battery can not always be charged to the desired maximum power as input and output conditions change. Although studies using a topology capable of boosting and stepping have been carried out, Buck-Boost converters or Sepic converters with relatively low efficiency have been used. In this paper, we propose a new Buck Boost combination power converter topology structure that can use Buck converter and Boost converter at the same time to improve inductor current ripple and power converter efficiency caused by wide voltage control range like solar charger.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.133-135
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• 2008

본 논문은 계통연계형 연료전지 PCS(Power Conditioning System)에서 최적의 승압효율을 갖는 Boost Converter의 설계를 위해 Boost Converter내의 각 소자의 선정에 따른 손실 및 분석을 통하여 최적의 소자선정 방법의 이해를 목적으로 한다. Boost Converter의 설계를 위한 소자선정을 위해 Or-CAD 16.0의 PSPICE Simulator을 사용하여 그 결과를 확인하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권8호
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• pp.423-429
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• 2006

Recently, the high frequency isolated boost DC/DC converter has been widely used for the PCS (Power Conditioning System) system because of its small size and low cost. However, the high frequency isolated boost DC/DC converters applied the conventional voltage-fed converter and current-fed converter have the problems such as the high conduction losses and the surge voltage due to the high circulating current and the leakage inductance, respectively. To overcome this problems, in this paper the secondary LLC resonant converter is proposed, and the experimental results of the secondary LLC series resonant converter for boost DC/DC converter are verified on the simulation based on the theoretical analysis and the 700W experimental prototype.

• 전기학회논문지
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• 제60권3호
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• pp.538-543
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• 2011

In this paper, design and control of an interleaved boost converter for multi-string PV Inverter are discussed. Interleaved Boost converter can reduce current ripples at input and output side by cancelling an each phase of inductor currents. Therefore, it contributes to increase efficiency and downsize the whole system volume, cost. One of the advantages of the multi-string system is easy to expand power capacity by connecting the converter modules in parallel. In order to reduce current ripples, the inductor currents on each phase are controlled independently in the converter module, and communication between the converter modules is required for further ripple current reduction. Current control algorithm for the balance of the each phase ripple currents and synchronization of the converter modules based on communication are proposed and implemented in the DSP programming. 10kW prototype of the multi-string converter module is assembled and experimental results are presented to verify the proposed ripple current reduction methods.