• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.323-324
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• 2016

In this paper a high efficiency bidirectional resonant converterfor Vehicle-to-Grid applications (V2G) is proposed.The proposed converter has adopted an LC auxiliary circuit in the third winding of the transformer. With the proposed method full softswitching can be ensured in all switches over a wide range of loadsand the secondary ringing can be removed with no additional snubber or clamp circuitry.In addition, since the proposed resonant converter is able to operate at an almost constant resonant frequencyregardless of the load, CC/CV charge of the battery can be simply implemented with high efficiency. A 3.3 kW bidirectional converter for On-Board Charger of Electric Vehicle is implemented to verify the validity of the proposed method. The experimental results show the high efficiency characteristics of the proposed converter over the wide range of load in both charge and discharge mode. The maximum efficiency of the proposed system was 98.13 % at 2.3 kW during the constant voltage mode charge operation.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.352-355
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• 2006

A new PWM-controlled quasi-resonant converter for high efficiency PDP sustaining power module is proposed in this paper. The load regulation of the proposed converter can be achieved by controlling the ripple of the resonant voltage across the resonant capacitor with hi-directional auxiliary circuit, while the main switches are operating at the fixed duty ratio and fixed switching frequency. Hence, the waveform of currents can be expected to be optimized on the conduction loss. Furthermore, the proposed converter shows the good ZVS capability, simple control circuits, no high voltage ringing problem of rectifier diodes, no DC offset of the magnetizing current and low voltage stress of power switches. In this paper, operational principles, analysis and design considerations are presented. Experimental results demonstrate that the output voltage can be controlled well by the auxiliary circuit as PWM method.

• Journal of Power Electronics
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• v.7 no.1
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• pp.28-37
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• 2007

A new PWM-controlled quasi-resonant converter for a high efficiency PDP sustaining power module is proposed in this paper. The load regulation of the proposed converter can be achieved by controlling the ripple of the resonant voltage across the resonant capacitor with a bi-directional auxiliary circuit, while the main switches are operating at a fixed duty ratio and fixed switching frequency. Hence, the waveforms of the currents can be expected to be optimized from the view-point of conduction loss. Furthermore, the proposed converter has good ZVS capability, simple control circuits, no high voltage ringing problem of rectifier diodes, no DC offset of the magnetizing current and low voltage stresses of power switches. In this paper, operational principles, features of the proposed converter, and analysis and design considerations are presented. Experimental results demonstrate that the output voltage can be controlled well by the auxiliary circuit using the PWM method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.473-477
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• 2007

The development of advanced Insulated Gate Bipolar Transistor(IGBT)has enabled high-frequency switching operation and has improved the performance of PWM inverters for motor drive. However, the high rate of dv/dt of IGBT has adverse effects on motor insulation stress. In many motor drive applications, the inverter and motor are separated and it requires long motor feds. The long cable contributes high frequency ringing at the motor terminal and it results in hight surge voltage which stresses the motor insulation. The inverter output filter and RDC snubber are conventional method which can reduce the surge voltage. In this paper, we propose the new low loss snubber to reduce the motor terminal surge voltage. The snubber consists of the series connection of charging/discharging capacitor and the voltage-clamped capacitor. At IGBT turn-off, the snubber starts to operate when the IGBT voltage reaches the voltage-clamped level. Since dv/dt is decreased by snubber operating, the peak level of the surge voltage can be reduced. Also the snubber operates at the IGBT voltage above the voltage-clamped level, the snubber loss is largely reduced comparing with RDC snubber. The proposed snubber enables to reduce the motor terminal surge voltage with low loss.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.6
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• pp.539-546
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• 1999

A new integrated single-stage zero current switched(ZCS) quasi resonant convertedQRC) for the IX)wer f factor correction(PFCl converter is introduced in this paper. The power factor correction can be achieved by t the discontinuous conduction mod$\varepsilon$(DCM) operation of an input current. The proposed converter has the c characteristics of the good IX)wer factor, 10씨 line current harmonics, and tight output regulation. Furthern10re, t the ringing effect due to the output capacitance of the main switch can be eliminated by use of‘ active clamp c circuit. Therefore, the proIX)sed converter is expecttc'(] to be suitable for a compact power converter with a t tightly regulated output voltage requiring a switching frequency of more than several hundrtc'(]s kHz.