• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.5
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• pp.136-144
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• 2010

This paper presents the two-switch interleaved active clamp forward converter, which is mainly composed of two active clamp forward converters. Only two switches are required, and each one is the auxiliary switch for the other. So, the circuit complexity and cost are reduced and control is more simple. An additional resonant inductance is employed to achieve ZVS(Zero-Voltage-Switching) during the dead times. Interleaved output inductor currents diminish the voltage and current ripple. Accordingly, the smaller output filter and capacitors lower the converter volume. This research proposed the Two-switch interleaved Active Clamp Forward Converter characteristic. The principle of operation, feature and design considerations is illustrated and the validity of verified through the experiment with a 160[W] based experimental circuit.

• Journal of Power Electronics
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• v.16 no.5
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• pp.1716-1724
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• 2016

This paper proposes both an active-switched quasi-Z-source inverter (AS-qZSI) and an extended active-switched qZSI (EAS-qZSI), which are based on the classic qZSI. The proposed AS-qZSI adds only one active switch and one diode to the classic qZSI for increasing the voltage boost capability. Compared with other topologies based on the switched-inductor/capacitor qZSI, the proposed AS-qZSI requires fewer passive components in the impedance network under the same boost capability. Additionally, the proposed EAS-qZSI is designed by adding one inductor and three diodes to the AS-qZSI, which offers enhanced boost capability and lower voltage stress across the switches. The performances of the two proposed topologies are verified by simulation and experimental results obtained from a prototype with a 32-bit DSP built in a laboratory.

• Journal of the Semiconductor & Display Technology
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• v.17 no.4
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• pp.56-61
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• 2018

In this paper, a new type of active snubber was proposed to lower the excessive rated voltage of the clamp capacitor which was a problem in the conventional circuit by applying auxiliary winding into the active snubber. A simplified equivalent circuit of the proposed snubber was derived by applying it to QR flyback converter, and the equivalent circuits for each switch state was shown under the steady-state condition. In addition, the maximum voltage of the clamp capacitor as well as the main switch was found by using the steady-state equations. In particular, it was found that the clamp capacitor voltage could be controlled by the auxiliary winding ratio. In order to verify the utility and practicality of the proposed converter with auxiliary winding type active snubber circuit, a prototype with an output voltage of 19V and a maximum load current of 6A was produced and the results were reported.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.250-252
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• 2002

Since DAS(Distribution Automation System) has been typically managed for feeder automation in passive manner, it has to be managed by operator when feeder over loadings are detected therefore it may be possible for propagating the over loaded area by operator's mistake. To overcome the defect, The author proposed the feeder switch automation using active database.

• Journal of Power Electronics
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• v.18 no.4
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• pp.955-964
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• 2018

In this paper, an active capacitor-diode-switch (CDS) snubber is proposed for L-type current-fed isolated DC-DC converters. The proposed CDS-clamped converter has a number of advantages. It can achieve wide range zero-voltage switching (ZVS) on two switches, a continuous input current with a low ripple, a reduction of one active switch and high efficiency. The operating principles, analysis and parameter design guideline are presented. A 300 W prototype is built to test the proposed converter. Simulation and experimental results are shown at 30 V input voltage and 400 V output voltage.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.520-522
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• 2008

A novel two-switch active clamp forward converter suitable for high input voltage applications is proposed. The main advantage of the proposed converter, compared to the conventional active forward converters, is that circuit complexity is reduced and the voltage stress of the main switches is effectively clamped to either the input voltage or the clamping capacitor voltage by two clamping diodes without limiting the maximum duty ratio. Also, the clamping circuit does not include additional active switches, so a low cost can be achieved without degrading the efficiency. Therefore, the proposed converter can feature high efficiency and low cost for high input voltage applications. The operational principles, features, and design considerations of the proposed converter are presented in this paper. The validity of this study is confirmed by the experimental results from a prototype with 200W, 375V input, and 12V output.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.277-279
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• 2008

In this paper, a novel active boost converter for SR drive is proposed. An active capacitor circuit is added in the front-end. Based on this active capacitor network, when boost switch turns off, this network seems as passive capacitor network. And the voltage of boost capacitor can keep balance with dc-link voltage automatically. In the capacitor network, discharging voltage is general dc-link voltage in parallel-connected capacitors; charging voltage is double dc-link voltage in series-connected capacitors. When boost switch turns on, two capacitors are connected in series, and discharging voltage is up to double dc-link voltage. So the fast excitation current can be obtained from this mode. Profit from fast excitation and fast demagnetization mode, the performance and output power can be improved. Some computer simulations are done to verify the performance of proposed converter.

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

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.505-507
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• 2008

A conventional active-clamp forward (ACF) converter is a favorable candidate in low-to-medium power applications. However, the switches suffer from high voltage stress, i.e., sum of the input voltage and the reset capacitor voltage. Therefore, it is not suitable for high input voltage applications such as a front-end converter of which the input voltage is about 400-$V_{dc}$. To solve this problem, three-switch ACF (TS-ACF) converter, which employs two main switches and one auxiliary switch with low voltage stress, is proposed. Utilizing low-voltage rated switches, the proposed converter is promising for high input voltage applications with high efficiency and low cost.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.258-261
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• 2001

High Power factor Active Filter converter is used for Inverter Air conditioner power supply to meet IEC standard. In the active filter topology for power factor, extra switch just control the input current indirectly to meet the IEC standard for reducing the cost and size. In this paper, low cost converter was suggested by simulation using extra switch which auxiliary pulse is inserted and quasi resonant soft switching topology control is adapted for panel's inverter air conditioner converter Inserting auxiliary Pulse method to the extra switch has the benefit of reducing THD by low cost input control circuit. And also quasi resonant soft switching topology can reduce switching loss. So both technical is suitable for Panel's Air conditioner.