• Proceedings of the KIPE Conference
• /
• 2007.11a
• /
• pp.34-36
• /
• 2007

A new soft switching boost converter is proposed in this paper. The conventional boost converter generates switching losses at turn on and off. Because of that, the whole system efficiency is reduced. The proposed converter utilizes soft switching method using an auxiliary switch and resonant circuit. Thus, the converter reduces switching losses lower than ones of hard switching method. The proposed soft switching boost converter can be applied to photovoltaic system, power factor correction circuit and so on.

• Journal of Power Electronics
• /
• v.7 no.4
• /
• pp.301-309
• /
• 2007

The flyback converter is one of the most attractive isolated converters in small power applications because of its simple structure. However, it suffers from high device stress, large transformer size, and high voltage stress across its switch and diode. To solve these problems a new cost-effective PWM single-switch isolated converter is proposed. The proposed converter has no output filter inductor, reduced voltage stress on the secondary devices, and reduced transformer size. Moreover, the switch turn-off loss is reduced and no dissipative snubber across the secondary diode is required. Therefore, it features a simple structure, a low cost, and high efficiency. The operational principle and characteristics of the proposed converter are presented and compared with the flyback converter and then verified experimentally.

• Proceedings of the KIPE Conference
• /
• 2017.11a
• /
• pp.119-120
• /
• 2017

기존 플라이백 컨버터를 사용하면 턴 오프 시 스위치의 드레인-소스 간 높은 과도 전압이 걸리고 이를 저감하기 위한 스너버 회로에서 높은 손실이 생긴다. 이를 해결하기 위해 변압기의 2차측 권선에 병렬로 연결된 캐패시터를 가지는 플라이백 컨버터를 제안한다. 본 논문은 2차측 캐패시터의 효과적인 설계 방법을 제시하고 기존 플라이백 컨버터 대비 저감되는 드레인-소스간 과도 전압 및 스너버 회로 전력 손실을 분석하여 제안하는 컨버터의 전력 변환 효율 증가 및 스위칭 소자의 스트레스가 저감됨을 보이고자 한다.

• Proceedings of the KIEE Conference
• /
• 2007.11c
• /
• pp.125-127
• /
• 2007

Presented increase and so on of switch stress and switching dissipation and EMI that is happened in general PWM converter and in this study to solve problem the resonance energy return to life rate and new active snubber PWM converter because do maximization. Active snubber PWM converter that try adds auxiliary switch and resonance capacitor, diode to existing converter under all switching conditions turn on/off Minimised switching dissipation that occur. Reduced harmonic components absorbing station recovery electric current that happen to snubber diode inserting diode and resistance. And decreased peak current that is happened in auxiliary switch arranging resonance capacitor and inductor properly, Certified effect that efficiency rises about 2.5[%] more than existent PWM converter in rated load through an experiment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.1
• /
• pp.23-28
• /
• 2008

In this paper, transient characteristics of the Punch Through Insulated Gate Bipolar Transistor (PT-IGBT) have been studied. On the contrary to Non-Punch Through Insulated Gate Bipolar Transistor(NPT-IGBT), it has a buffer layer and reduces switching power loss. It has a simple drive circuit controlled by the gate voltage of the MOSFET and low on-state resistance of the bipolar junction transistor. The transient characteristics of the PT-IGBT have been analyzed analytically. Excess minority carrier and charge distribution in active base region, the rate of anode voltage with time are expressed analytically by adding the influence of buffer layer. The experimental data is obtained from manufacturer. The theoretical predictions of the analysis have been compared with the experimental data obtained from the measurement of a device(600 V, 15 A) and show good agreement.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.8 no.1
• /
• pp.48-55
• /
• 2003

The design and analysis of a three-phase 6/8 structure SRM(switched reluctance motor) art described. The range of the stator ole arc and the rotor pole arc of the motor we analyzed in the linear region. The optimum range of the stator pole arc and the turn-off angle of the main switches in the power converter are given with the 2-D finite element electro-magnetic field calculation of the motor and the nonlinear simulation. Test results of the prototype are discussed. This type is good for high efficiency drive because the drive circuit is simple and current density and copper loss of the winding are law.

• Proceedings of the KIEE Conference
• /
• 1999.07f
• /
• pp.2638-2640
• /
• 1999

This paper proposes a current-fed type high frequency inverter using a soft switching technology Zero-Voltage-Switching to reduce turn on and off loss at the switching. The analysis of the proposed circuit was described by using normalized parameter and operating characteristics have been evaluated as to switching frequency and parameters. In the future, the proposed circuit is considered to be useful for induction heating applications.

• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.563-564
• /
• 2008

This paper presents a new Insulated Gate Bipolar Transistor(IGBT) for power switching device based on Non Punch Through(NPT) IGBT structure. The proposed structure has adding N+ beside the P-base region of the conventional IGBT structure. The proposed device has faster turn-off time and lower forward conduction loss than the conventional IGBT structure.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.14 no.2
• /
• pp.89-95
• /
• 1978

A SCR static breaker was studied on the Resistive and inductive load, then on the overload break circuit using operational Amplifier. In this paper, the principal circuit required for forced commutation was voltage commutation by the introduction of a parallel Capacitor. The results obtained are follows; 1. In thecondition that the tima constant of R-C circuit is larger than the turn off time of SCR, the breaker has low transient phenomena and no recovery vol age. 2. By using OP Amplifier on the load circuit, overcurrent trip point will be able to adjust to the wide range of over current. 3. In the over current qrcuit, the power loss was reduced remarkably.

• Proceedings of the KIEE Conference
• /
• 1998.07f
• /
• pp.1911-1913
• /
• 1998

This paper has described about a SEPP Inverter for induction heating load. It is analyzed theoretically about the Inverter operation for induction heating. According to the parameters of induction heating load, it is proposed a method of circuit analysis and operation characteristics of the Inverter. In addition, the soft switching technology known as ZVS(Zero Voltage Switching) is used to reduce turn on and off loss at switching. The Proposed inverter shows it can be practically used as power source system for high frequency induction heating appliancs.