• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.50 no.4
• /
• pp.179-187
• /
• 2001

In recent years, the switching source devices have the advantage of small, light and high reliability with the high-frequency. But, high-frequency switching has disclosed disadvantage of result from stress and turn-on and turn-off peak losses at the switching instant. Accordingly, in this paper propose ZVS-HB type high-frequency resonant DC/DC converter using soft switching technique (Zero-Voltage-Switching, Zero-Current-Switching) with safety operating of circuit at diving on inductive zone, through the circuit design example using the capacitor $C_3,\;C_4$ with soft switching function and division characteristic of resonant Capacitor C, $C_1,\;C_2$, and, the characteristic analysis of circuit is generally described using normalized parameters. Also, this paper certified a rightfulness of characteristic analysis in comparison with a theoretical values and a experimental values obtain from experiment using MOSFET.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.11a
• /
• pp.377-382
• /
• 2005

This paper presents two new circuit topologies of DC bus lineside active edge resonant snubber assisted soft-switching PWM full-bridge DC-DC converter acceptable for either utility AC 200V-rms or AC 400V-rms input voltage source. One topology of proposed DC-DC converters is composed of a typical voltage source-fed full-bridge high frequency PWM inverter using DC busline side series power semiconductor switching devices with the aid of a parallel capacitive lossless snubber. All the active power switches in the full-bridge arms and DC busline can achieve ZCS turn-on and ZVS turn-off commutations and the total turn-off switching power losses of all active switches can be reduced for high-frequency switching action. It is proved that the more the switching frequency of full-bridge soft switching inverter increases, the more soft-switching PWM DC-DC converter with a hish frequency transformer link has remarkable advantages for its efficiency and power density as compared with the conventional hard-switching PWM inverter type DC-DC converter

• Proceedings of the KIPE Conference
• /
• 2011.07a
• /
• pp.438-439
• /
• 2011

In this paper, soft switching bidirectional DC-DC converter is proposed. The proposed topology is added two auxiliary switches, two resonant capacitors and one resonant inductor to convectional bidirectional DC-DC converter. Therefore, this proposed topology can reduce switching loss of each power switch by ZVS (Zero Voltage Switching) and ZCS (Zero Current Switching). We have performed mode analysis, simulation and experiment for the proposed topology.

• Journal of Power Electronics
• /
• v.18 no.3
• /
• 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.

• Proceedings of the KIEE Conference
• /
• 1998.07f
• /
• pp.2036-2038
• /
• 1998

In the buck-boost DC-DC chopper which is used at a certain situation such as in factories where loads often change a lot, the switches in the device make big energy loss in operating at Buck-Boost Mode due to hard switching and are affected by lots of stresses which decrease the efficiency rate of the converter. In order to improve this problem, to decrease the loss of snubber and switching, it has been investigated that zero voltage switching mode and zero current switching mode which make the operation of switches with soft switching. For the more sophisticated and advanced device, this paper is presented the Partial Resonant Soft Switching Mode Power Converter which is adapted the power converter having the partial resonant soft switching mode, that makes switches operate when the resonant current or voltage becomes zero by making the resonant circuit partially at turning on and off of the switches with suitable layout of the resonant elements and switch elements in the converter. Also, this paper includes the analysis and simulation of the Partial Resonant type Buck-Boost Chopper.

• Proceedings of the KIEE Conference
• /
• 2006.04b
• /
• pp.278-280
• /
• 2006

In this paper, a novel type of auxiliary active snubbingcircuit assisted quasi-resonant soft-switching pulse width modulation inverter is proposed for consumer induction heating equipments. The operation principle of this high frequency inverter is described using switching modes and equivalent circuits. This newly developed series resonant high frequency inverter can regulate its high frequency output AC power under a principle of constant frequency active edge resonant soft- switching commutation by asymmetrical PWM control system. The high frequency power regulation and actual power conversion efficiency characteristics of consumer induction heating (IH) products using the proposed soft-switching pulse width modulation (PWM) series load resonant high frequency inverter evaluated. The practical effectiveness and operating performance of high frequency inverter are discussion on the basis of simulation and experimental results as compared with the conventional soft-switching high frequency inverter.

• Journal of Power Electronics
• /
• v.18 no.2
• /
• pp.364-374
• /
• 2018

A novel passive lossless soft-switching single inductor dual buck full-bridge inverter (PLSSIDBFBI) is presented in this paper. To accomplish this, a passive lossless snubber circuit is added to a dual buck full-bridge inverter. Therefore, the advantages of the dual buck full-bridge inverter are included in the proposed inverter, and the inverter has just one filter inductor, which can decrease the system volume and improve the integration. In addition, the passive lossless snubber circuit achieves soft-switching by its own resonance, and all of the energy stored in the passive lossless snubber circuit can be transferred to load. A comparison between eight topologies is performed in this paper, and the analysis shows that the proposed soft-switching inverter topology has high reliability and efficiency. Finally, experimental results obtained with a 1 kW prototype verify the theoretical analysis and demonstrate the prominent characteristics of a reduced switching loss and improved efficiency.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.922-923
• /
• 2008

This paper is proposed to a novel DC-DC buck-boost converter added electric isolation by using a soft switching method. To be achieved of high efficiency system, the proposed converter is constructed by using a partial resonant circuit. The control switches using in the converter are operated with soft switching for a partial resonant method. The controlling switches are operated without increasing their voltage and current stresses by the soft switching technology. The result is that the switching loss is very low and the converter efficiency is high. And the proposed converter is added in a electric isolation. When the power conversion system is required to electric isolation, the proposed converter is adopted with system development of high efficiency. The soft switching operation and the system efficiency of the proposed converter is verified by digital simulation and experimental results.

• Proceedings of the KIPE Conference
• /
• 2006.06a
• /
• pp.200-202
• /
• 2006

In this paper, a novel type of auxiliary active snubbing circuit assisted quasi-resonant soft-switching pulse width modulation inverter is proposed for consumer induction heating equipments. The operation principle of this high frequency inverter is described using switching modes and equivalent circuits. This newly developed series resonant high frequency inverter can regulate its high frequency output AC power under a principle of constant frequency active edge resonant soft-switching commutation by asymmetrical PWM control system. The high frequency power regulation and actual power conversion efficiency characteristics of consumer induction heating (IH) products using the proposed soft-switching pulse width modulation (PWM) series load resonant high frequency inverter evaluated. The practical effectiveness and operating performance of high frequency inverter are discussion on the basis of simulation and experimental results as compared with the conventional soft-switching high frequency inverter.

• Journal of Power Electronics
• /
• v.15 no.3
• /
• pp.602-609
• /
• 2015

In this paper, a zero current transition (ZCT) double-ended flyback converter is proposed. All of the switching elements act under soft switching conditions and the voltage stress of the main switches is limited to the input voltage due to the innate behavior of the double-ended flyback converter. Providing soft switching conditions and clamping the voltage stress improves the efficiency and electromagnetic compatibility (EMC). The Proposed converter is analyzed in detail and its operating modes are discussed in detail. Experimental results are presented to verify the theoretical predictions. Moreover, the conducted electromagnetic emissions of the proposed ZCT double-ended flyback converter are measured to show another merit of the proposed converter in addition to providing soft switching conditions. The measured electromagnetic interference (EMI) of the proposed converter demonstrates that its EMI is lower than the conventional double-ended flyback converter. Furthermore, two simple and cost effective EMI reduction methods are applied to satisfy the EMC standard.