• 전기전자학회논문지
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• 제27권4호
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• pp.450-455
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• 2023

태양광 패널의 큰 기생 커패시턴스에 기인하는 과도한 누설 전류를 피하기 위한 단상 태양광 인버터 중에 부스트 컨버터와 하프브리지 인버터를 종속적으로 결합하는 방식은 가장 단순하면서 누설 전류가 가장 작다. 하지만 직류단 전압이 높아 스위칭 소자의 정격 전압이 높고 스위칭 손실이 크다. 본 논문은 부스트 컨버터를 제거하는 대신에 하프브리지 인버터의 출력 측에 2개의 양방향 스위치를 추가함으로써 벅부스트 인버터로 동작할 수 있는 새로운 회로 토폴로지를 제안한다. 고전압 직류단을 거치는 두 단계의 전력 변환을 한 단계로 줄인 덕분에 전력 손실을 절감할 수 있으며 비용 및 누설 전류는 증가하지 않는다. 제안된 회로 토폴로지의 타당성은 컴퓨터 시뮬레이션 및 전력 손실 계산을 통해 검증한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.694-700
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• 1998

A novel zero-voltage-transition (ZVT) isolated PWM boost converter for single stage power factor correction (PFC) is presented to improve the performance of the previously presented ZVT converter[8]. A simple auxiliary circuit which includes only one active switch provides zero-voltage-switching (ZVS) condition to all semiconductor devices. (Two active switches are required for the previous ZVT converter) This leads to reduced cost and simplified control circuit comparing to the previous ZVT converter. The ZVS is achieved for wide line and load ranges with minimum device voltage and current stresses. Operation principle, control strategy and features of the proposed converter are presented and verified by the experimental results from a 1.5 kW, 100 KHz laboratory prototype.

• 전기학회논문지P
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• 제51권4호
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• pp.186-192
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• 2002

In this paper, interleaved boost power factor corrector(IBPFC) is applied as a pre-regulator in switch mode power supply. IBPFC can reduce input current ripple and effectively increase the switching frequency without increasing the switching losses, because input current is divided each 50% by two switching devices. IBPFC can be classified as three cases by duty ratio condition in continuous current mode and be carried out state space average modeling. According to the modeling, steady and transient state analysis is performed by steady elements and perturbation element. Control transfer function is derived for design of control system.

• Journal of Power Electronics
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• 제14권4호
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• pp.621-631
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• 2014

To invigorate the tapped-inductor boost (TIB) topology in emerging high step-up applications for off-grid products, a lossless snubber consisting of two capacitors and three diodes is proposed. Since the switch voltage stress is minimized in the proposed circuit, it is allowed to use a device with a lower cost, higher efficiency, and higher availability. Moreover, since the leakage inductance is fully utilized, no effort to minimize it is required. This allows for a highly productive and cost-effective design of the tapped-inductor. The proposed circuit also shows a high step-up ratio and provides relaxation of the switching loss and diode reverse-recovery. In this paper, the operation is analyzed in detail, the steady-state equation is derived, and the design considerations are discussed. Some experimental results are provided to confirm the validity of the proposed circuit.

• 전력전자학회논문지
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• 제18권5호
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• pp.485-491
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• 2013

A new passive lossless snubber for boost converter based on magnetic coupling is proposed. It is composed of a winding coupled with boost inductor, one snubber inductor, two snubber capacitor and three additional diodes. Especially, the snubber inductor can not only limit the reverse recovery current of output diode but also minimize switch turn-on losses greatly. Moreover, all of the energy stored in the snubber is transferred to the load in the manner of resonance. To confirm the validity of proposed system, theoretical analysis, design consideration, and verification of experimental results are presented.

• 조명전기설비학회논문지
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• 제27권10호
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• pp.59-68
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• 2013

This paper proposes the boost type bidirectional DC/DC converter with high efficiency for electric vehicle using an interleave method. This interleave method can reduce the system size because it reduces the ripple of output voltage and input current with no add to extra filter. Proposed system is consist of two converters and applies to interleaved method through phase shift to each converter. And it implements the high boost through voltage double and series construction of output port. Also, it reduces the price and increases the efficiency as operating the ZCS by leakage inductance of transformer and capacitor of voltage double with not add special reactor. Proposed DC/DC converter using interleave method is proved the validity through the result of PSIM simulation and experiment of 5kW DC/DC converter.

• Journal of Power Electronics
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• 제18권3호
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• pp.681-693
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• 2018

This paper proposes a soft-switching bidirectional dc-dc converter (BDC) with an auxiliary circuit. The proposed BDC can achieve the zero-voltage switching (ZVS) using an auxiliary circuit in the buck and boost operations. The auxiliary circuit supplies optimal energy for the ZVS operation of the main switches. The auxiliary circuit consists of a resonant inductor, a back-to-back switch and two capacitors. A small-sized resonant inductor and an auxiliary switch with a low-rated voltage can be used in the auxiliary circuit. Zero-current switching (ZCS) turn-on and turn-off of the auxiliary switches are possible. The proposed soft-switching scheme has a look-up table for optimal switching of the auxiliary switches. The proposed strategy properly adjusts the turn-on time of the auxiliary switch according to the load current. The proposed BDC is verified by the results of PSIM simulations and experiments on a 3-kW ZVS BDC system.

• 전력전자학회논문지
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• 제7권4호
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• pp.346-352
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• 2002

본 논문에서는 정류용 다이오드의 역 회복시 발생하는 손실을 줄이기 위한 새로운 듀얼 모드로 동작하는 ZCS-PWM 승압형 컨버터를 제안한다 제안된 회로에서 각각의 스위치는 소프트 스위칭 조건에서 매 사이클마다 교번으로 스위칭 동작을 하고 스위치 $S_2$에 직렬로 공진형 인덕터 Lr을 달아서 스위칭 손실과 EMI 노이즈와 관련된 정류용 다이오드$(D, D_1)$의 역 회복 전류를 감소시켰다. 제안된 컨버터는 기존의 ZVT-PWM 컨버터$^{[2]}$에 수동 및 능동 소자를 더 이상 추가하지 않기 때문에 각 소자들이 받는 전류/전압 스트레스는 기존의 하드 스위칭 컨버터 같다. 본 논문에서는 제안된 회로의 동작을 분석하고 이를 바탕으로 제작 및 실험을 통해서 타당성을 입증하였다.

• 전기학회논문지
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• 제67권4호
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• pp.531-537
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• 2018

This paper propose a bidirectional dc-to-dc converter employing dual inductor for current ripple reduction. Conventional bidirectional dc-to-dc converter uses a single inductor for two different modes; boost and buck; therefore it is difficult to satisfy the optimized inductance value for each mode. To improve this problem, the proposed converter adds two switches, a diode, and one inductor. By proper switching of the additional switch, the proposed converter operates with a inductor in boost mode, but it works with dual inductor in buck mode. Hence in both modes the proposed bidirectional converter can be operated with optimized inductance values. Most of all the optimized inductance in buck mode can reduce the current ripple and its effective value(rms), which are directly related to the temperature increase resulted in short lifetime of battery. To verify the validity of the proposed approach, we first analyzes the operation of the proposed converter theoretically, and implement computer-aided simulations and experiments using a prototype.

• Journal of Power Electronics
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• 제7권2호
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• pp.174-180
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• 2007

In this paper, a simple control method for two-stage utility grid-connected photovoltaic power conditioning systems (PCS) is proposed. This approach enables maximum power point (MPP) tracking control with post-stage inverter current information instead of calculating solar array power, which significantly simplifies the controller and the sensor. Furthermore, there is no feedback loop in the pre-stage converter to control the solar array voltage or current because the MPP tracker drives the converter switch duty cycle. This simple PCS control strategy can reduce the cost and size, and can be utilized with a low cost digital processor. For verification of the proposed control strategy, a 2.5kW two-stage photovoltaic grid-connected PCS hardware which consists of a boost converter cascaded with a single-phase inverter was built and tested.