• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.1
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• pp.36-43
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• 2017

This paper describes a hybrid multi-output three-level DC/DC converter suitable for a wide, high-input voltage range of an auxiliary power supply for a high-power photovoltaic generating system. In a high-power photovoltaic generating system, the solar panel output voltage depends on solar radiation quantity and varies from 450Vdc to 1100Vdc. The proposed hybrid multi-output three-level DC/DC converter, which is an auxiliary power supply, would be used as power source for control printed circuit boards and relay and cooling fans in a high-power photovoltaic generating system. The proposed multi-output ($24V_{DC}/30A$, $230V_{DC}/5A$) hybrid three-level boost converter, which uses an energy recovery snubber, is controlled by variable-frequency and phase-shifted modulations and can achieve zero-voltage switching with all operating conditions of input voltage and load range. Experimental results of a 2kW prototype are evaluated and implemented to verify the performance of the proposed converter.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.1
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• pp.117-125
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• 1998

In this paper, in order to develop the three phase GTO CSI of high efficiency 1M drive with low loss commutation and snubber energy, we studied the energy recovery circuit to recover stored energy in clamping capacitor and DC link inductor(VCC-l and VCC-2), and snubber capacitor(VCC-3). By using an induction motor as the load of inverter, experimental results show that dissipated DC power is decreased and capacitor voltage Vc is effectively suppressed by VCC-2 and VCC-3 system, and the validity of VCC-3 system with low loss commutation and snubber energy is proofed.roofed.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.1
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• pp.64-73
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• 2001

This paper presents a Zero Voltage and Zero Current Switching (ZVZCS) 3-Level DC/DC converter. This converter overcomes the drawbacks presented by the conventional Zero Voltage Switching(ZVS) 3-Level converter, such as high circulating energy, severe parastic ringing on the rectifier diodes, and limited ZVS load range for the inner switches. The converter presented in this paper uses a phase shift control with a flying capacitor in the primary side to achieve ZVS for the outer switches. Additionally, the converter uses an energy recovery snubber to reset the primary current during the free-wheeling stage to achieve ZCS for the inner switches. The proposed converters are analyzed and verified on 6kW, 39kHz experimental prototype.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.1042-1046
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• 1998

A new soft switching isolated bi-directional phase shifted pulse width modulation (PSPWM) dc/dc converter is presented. Due to the use of the energy recovery snubber, the isolated bi-directional PSPWM dc/dc converter has a significant reduction of switching losses in the switching devices of the primary and secondary side bridge, respectively. The proposed soft switching bi-directional PSPWM FB dc/dc converter provides an energy recovery snubber which consists of two fast recovery diodes, a resonant capacitor and a resonant inductor. The complete operating principles and simulation results will be presented.

• Journal of Power Electronics
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• v.4 no.4
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• pp.237-245
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• 2004

In this paper, a two-switch high frequency flyback transformer linked zero voltage soft switching PWM DC-DC power converter implemented for distributed DC- feeding power conditioning supplies is proposed and discussed. This switch mode power converter circuit is mainly based on two main active power semiconductor switches and a main flyback high frequency transformer linked DC-DC converter in which, two passive lossless quasi-resonant snubbers with pulse current regeneration loops for energy recovery to the DC supply voltages composed of a three winding auxiliary high frequency pulse transformer, auxiliary capacitors and auxiliary diodes for inductive energy recovery discharge blocking due to snubber capacitors are introduced to achieve zero voltage soft switching from light to full load conditions. It is clarified that the passive resonant snubber-assisted soft switching PWM DC-DC power converter has some advantages such as simple circuit configuration, low cost, simple control scheme, high efficiency and lowered noises due to the soft switching commutation. Its operating principle is also described using each mode equivalent circuit. To determine the optimum resonant snubber circuit parameters, some practical design considerations are discussed and evaluated in this paper. Moreover, through experimentation the practical effectiveness of the proposed soft switching PWM DC-DC power converter using IGBTs is evaluated and compared with a hard switching PWM DC-DC power converter.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.635-638
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• 2005

An energy recovery sustaining driver with zero current switching to reduce switching losses and EMI is presented in this paper. The driver with designed snubber circuits reduces ringing voltage significantly on PDP so that the voltage rating of MOSFETs can be lower as well to reduce the cost of switches.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.133-136
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• 2002

This paper presents m improved soft switching Buck converter using an energy recovery snubber which is composed of a tapped inductor, two snubber capacitors and three snubber diodes. The proposed Buck converter achieves zero voltage turn-of in the main power switch md freewheeling diode. The operating Principle of the Proposed Buck converter is described through the simulation, relevant equation and analysis.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.1
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• pp.10-18
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• 2016

In this study, an efficient clamp is proposed to reduce the switch voltage stress of a forward converter. The proposed clamp consists of a conventional LC snubber, a tertiary winding, and a diode. When the switch is turned OFF, the magnetizing inductor energy of the transformer is recovered directly into the flyback output, which is the tertiary winding and diode network, instead of circulating in the LC snubber. Therefore, switch voltage stress and circulating current caused by the magnetizing inductor energy are reduced. This condition improves the efficiency of the forward converter with limited switch voltage stress. A theoretical analysis and the design guidelines of the proposed converter are provided. Experimental results are also reported.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.403-404
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• 2016

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2169-2171
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• 1998

In order to improved the three phase GTO CSI of high efficiency IM drive with low loss commutation and snubber energy, we studied the energy recovery circuit to recover stored energy in clamping capacitor, dc link inductor and snubber capacitor, used an induction motor as the load of inverter. Specially, we investigated how dc input power is increased or decreased according to size of dc link inductor. The validity of this system is proved through experiment.