• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.3
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• pp.224-230
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• 2016

In this study, a single-power-conversion series-resonant ac-dc converter with high efficiency and high power factor is proposed. The proposed ac-dc converter consists of single-ended primary-inductor converter with an active-clamp circuit and a voltage doubler with series-resonant circuit. The active-clamp circuit clamps the surge voltage and provides zero-voltage switching of the main switch. The series-resonant circuit consists of leakage inductance $L_{lk}$ of the transformer and resonant capacitors $ C_{r1}$ and $ C_{r2}$. This circuit also provides zero-current switching of output diodes $D_1$ and $D_2$. Thus, the switching loss of switches and reverse-recovery loss of output diodes are considerably reduced. The proposed ac-dc converter also achieves high power factor using the proposed control algorithm without the addition of a power factor correction circuit and a dc-link electrolytic capacitor. A detailed theoretical analysis and the experimental results for a 1kW prototype are discussed.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1200-1206
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• 2015

This paper proposes an actively clamped two-switch flyback converter. Compared to the conventional two-switch flyback converter, the proposed two-switch flyback converter operates with a wide duty cycle range. By using an active-clamp circuit, the proposed converter achieves zero-voltage switching for all of the power switches. Zero-current switching of an output diode is also achieved. Thus, compared with the conventional converter, the proposed converter realizes a higher efficiency with an extended duty cycle. The performance of the proposed converter is verified by the experimental results with use of a 1.0 kW prototype circuit.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.247-250
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• 1997

A novel zero-voltage-switching(ZVS) isolated PWM converter for single stage power factor correction (PFC) is presented to improve the performance of the previously presented ZVT converter[5]. A simple clamp circuit in the primary side provides zero-voltage-switching condition to all semiconductor devices. This ZVS is achieved with minimum device voltage and current stresses. Operation principle, control strategy and features of the proposed converter are presented and verified by the experimental results from a 1.5 ㎾, 100 KHz laboratory prototype

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.136-139
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• 2001

The voltage resonating inverter has a defect in the switching element that works at 5 or 6 times higher than input voltage. Especially, it is very difficult to choose very high switching device for the 220[V]commercial voltage. In this paper, it is proposed the optimum method to realize the turbo 2000[W] power for induction cooker that is employed the 900[V] IGBT with decreasing operating voltage of the switching component by making the 220[V], 1500[W] inverter through the clamp mode voltage resonating inverter.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.5
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• pp.351-357
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• 2004

In this paper, we present an analytical method that provides fast and efficient evaluation of the conversion efficiency for switching power supplies. In the proposed method, the conduction losses are evaluated by calculating the effective values of the ideal current waveform first and incorporating them into an exact equivalent circuit model of the switching power supply that includes all the parasitic resistances of the circuit components. While the winding losses and core losses are accurately accounted for the magnetic components, the skin and proximity effects are assumed to be negligible in order to simplify the analysis. The validity and accuracy of the proposed method are verified with experiments on a prototype active-clamped forward converter with synchronous rectification. An excellent correlation between the experiments and theories are obtained for the input voltages of 36-75 V with 4-6 MOSFETs employed for the synchronous rectification.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.807-810
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• 2004

This is a experimental result which is reported with using 16-Bit microprocessor H8 series of Renesas company, organizing digital control which is practicable PWM embodiment, and applying switched-mode power supply. The basic topology consists of the active clamp forward DC-DC converter which is widely used for the highly efficient power supply these days. In an experiment, it incites the result to lay emphasis on the highly efficient operation of converter, and performance of digital control which is practicable PWM embodiment. And it is debated on performance of processor and condition for improving performance of part.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.403-405
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• 2008

This paper proposes an output inductor-less active clamp forward converter employing current boost-up circuit for high power density adaptor. By applying the proposed current boost-up circuit, the proposed converter has low conduction loss and low voltage ringing of the secondary rectifier. This paper presents the analysis of the proposed converter and a comparison between the proposed converter and the conventional converter through experiment.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.374-377
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• 2002

This paper presents dynamic analyses and control design of the current-mode controlled active-clamp forward-flyback converter. The circuit averaging technique is used to extract the small-signal circuit model for the power stage From the small-signal circuit model of the power stage, the open-loop transfer functions are derived and used for the compensation design. The analysis results are verified using an experimental converter that delivers a 3.3V/10A output from a $40\~60V$ input source.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.433-435
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• 2005

A new high efficiency active clamp forward converter suitable for the sustaining power module(SPM) of a plasma display panel (PDP) is proposed. It has a wide zero voltage switching (ZVS) range without inserting additional resonant inductor. Also, it features simpler structure, lower cost, less mass, and no effective duty loss. Furthermore, voltages across all rectifier diodes are clamped on the output voltage, which results in a higher efficiency.

• Proceedings of the KIEE Conference
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• summer
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• pp.1269-1271
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• 2004

This is a thesis experiment result which is reported with using 16-Bit microprocessor H8 series of Renesas company, organizing digital control which is practicable PWM embodiment, and applying switched-mode power supply. The basic topology consists of the active clamp forward DC-DC converter which is widely used for the highly efficient power supply these days. In an experiment, it incites the result to lay emphasis on the highly efficient operation of converter, and performance of digital control which is practicable PWM embodiment. And it is debated on performance of processor and condition for improving performance of part.