• Smart Structures and Systems
• /
• 제26권4호
• /
• pp.521-531
• /
• 2020

In this paper, a new interleaved high step-up converter with low voltage stress on the switches is proposed. In the proposed converter, soft switching is provided for all switches by just one auxiliary switch, which decreases the conduction loss of auxiliary circuit. Also, the auxiliary circuit is expanded on the converter with more input branches. In the converter all main switches operate under zero voltage switching condition and auxiliary switch operate under zero current switching condition. Because of the interleaved structure, the reliability of converter increases and input current ripples decreases. The clamp capacitor in the converter not only absorb the voltage spikes across the switch due to leakage inductance, but also improve voltage gain. The proposed converter is fully analyzed and to verify the theoretical analysis, a 100 W prototype was implemented. Also, to show the effectiveness of auxiliary circuit on conduction EMI, EMI of the proposed converter comprised with hard switching counterpart.

• Journal of Power Electronics
• /
• 제18권3호
• /
• pp.681-693
• /
• 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
• /
• 제24권4호
• /
• pp.294-302
• /
• 2019

A capacitor common connected LLC resonant converter with auxiliary switches for a wide output voltage control range is presented in this paper. The proposed converter can be controlled in two ways to achieve a wide output voltage control range of Vo-3Vo. The first control method is performed through pulse width modulation of the auxiliary switches and primary switching devices. The second control method is conducted through frequency modulation of the primary switching devices configured to operate in full-bridge switching modes, when the auxiliary switches are turned off. The feasibility of the proposed converter is verified by the experimental results of a 5 kW prototype.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.155-158
• /
• 2004

This paper proposes a soft-transition control strategy for a three phase ZCS(Zero Current Switching) inverter circuit. Each phase leg of inverter circuit consists of an LC resonant tank, two main switches, and two auxiliary switches. This paper presents design consideration via a study example of a three phase prototype inverter for motor drives. A simple device tester with zero current switching capability is proposed to select eligible auxiliary switches. The principle of operation, feature and design consideration is illustrated and verified through the experiment with a 2.2kW 5kHz IGBT based experimental circuit.

• 전기학회논문지
• /
• 제67권12호
• /
• pp.1611-1618
• /
• 2018

This paper proposes a new auxiliary resonant commutated pole (ARCP) inverter which has a modified auxiliary circuit. The proposed auxiliary circuit includes two auxiliary IGBT switches, an LC resonant circuit, and two clamping diodes. In order to analyze the performance of proposed ARCP inverter, computer simulations with PSCAD, and hardware experiments were carried out. Through analyzing the experimental results, it is known that the proposed ARCP inverter offers efficiency improvement of 1.5% compared with the hard-switching inverter.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2003년도 추계학술대회 논문집(III)
• /
• pp.646-652
• /
• 2003

AS a main Power Supply of the Railroad Vehicles, a three-Level ZVZCS DC/DC Converter is proposed in this paper. The proposed three-Level DC/DC Converter achieves zero voltage and zero current switching for the main switches. Its attribute is that the voltage across the switches is half the value of the input voltage. Also. using a diode and secondary side of the transformer, and simple auxiliary circuits it achieves zero current switching of the auxiliary switches. The principle operation and simulation results are included.

• 전력전자학회논문지
• /
• 제23권4호
• /
• pp.256-264
• /
• 2018

This paper proposes a three-bridge LLC resonant converter with auxiliary switches for a wide output voltage control range. This converter can be controlled in two ways to achieve a wide controllable output voltage control range of $V_o$ to $3V_o$. The first control mechanism is achieved through the pulse width modulation (PM) of the auxiliary switches and primary switching devices, while the second control mechanism is achieved through the frequency modulation (FM) of the primary switching devices that are configured to operate in the full-bridge switching mode when the auxiliary switches are turned off. The feasibility of using the proposed converter is verified by the results of an experiment with a 2kW prototype.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 B
• /
• pp.1002-1004
• /
• 2001

In conventional zero-current-switching(ZCS) PWM converters, the switching loss, stress and noise can't be minimized because they adopt auxiliary switches operated in hard-switching. In this paper, new ZCS-PWM converters of which auxiliary switches always operate with soft-switching are proposed. Therefore, the proposed ZCS-PWM converters are most suitable for systems requiring high-power density. The characteristics of these converters are verified by experimental results.

• 전자공학회논문지SC
• /
• 제42권2호
• /
• pp.49-58
• /
• 2005

새롭게 개발되어진 소프트 스위칭 3상 PM 정류기는 간단한 회로 구성과 고효율을 가지고 있다. 제안한 회로는 ARCP 컨버터의 한 종류이다. 기존의 ARCP 컨버터는 3상 보조 리액터와 소프트 스위칭 보조 회로를 6개의 보조 스위치, 각 스위치의 게이트 구동 회로, 제어회로가 필수적이나 결과적으로 이 회로는 높은 손실을 가지고 있다. 본 논문에서 제안한 주 회로는 두 개의 보조 리액터와 두 개의 스위치와 각각의 다이오드로 구성되는 보조 소프트 스위칭 회로이다. 부가적으로 두 개의 주 스위치와 간단한 보조 스위치의 제어회로는 PWM 제어 회로로 만들어지며, 공통으로 사용하였다. 소프트 스위칭 보조 회로의 작용을 의미하며, 주 스위치는 WS로 동작되고, 보조스위치는 ZCS로 동작된다. 본 논문에서 제안한 회로의 구성과 동작 원리를 설명하였으며, 실험결과에 의해서 증명하였다 용랑5[kW]의 시작품을 사용하여 변환효율은 최대$98.8[\%]$과 역률$99[\%]$를 얻었다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2016년도 전력전자학술대회 논문집
• /
• pp.405-406
• /
• 2016

A bidirectional secondary LLC resonant converter with auxiliary switches and an additional inductor is proposed to achieve the high gain characteristics of LLC resonant convertors. Auxiliary switches, an additional inductor and a resonant capacitor are connected in the high voltage secondary side of the proposed converter. The ac analysis and operating characteristics of bidirectional secondary LLC resonant converter are investigated. A 1kW prototype bidirectional secondary LLC resonant converter connected to the $400V_{DC}$ buses is designed and tested to confirm the validity and applicability of the proposed converter.