• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.3
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• pp.40-49
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• 2011

This paper presents novel circuit topology of half-bridge soft-switching PWM inverter type DC-DC high power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed, half-bridge high frequency PWM inverter with a high frequency planar transformer link PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode-equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC bus lines can achieve ZCS turn-on and ZVS turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, high switching frequency IGBTs can actually be selected in the frequency range of 40[kHz] under the principle of soft-switching. The performance evaluations of the experimental setup are illustrated practically.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.298-302
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• 2004

In this paper, AC electric vehicle propulsion system(Converter/Inverter) using high power semiconductor, UM(Intelligent Power module) is proposed. 2-Parallel operation of two PWM converter is adopted for increasing capacity of system and the VVVF inverter control is used a mixed control algorithm, where the vector control strategy at low speed region and slip-frequency control strategy at high speed region. The proposed propulsion system is verified by experimental results with a 1,350kW converter and 1,100kVA inverter with four 210kW traction motors.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.526-528
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• 2008

LLC series resonant converter has many unique characteristics and improvement over PWM topologies. However, many output capacitors should be needed in parallel to satisfy an output voltage ripple and a rated ripple current of the capacitors. This paper is deal with a novel two phase interleaved LLC resonant converter using a phase of the resonant capacitor. The proposed converter can satisfy output voltage ripple and a rated ripple current of capacitors with few output capacitors, relatively. The operation and features is considered in detail and a prototype with a 12V-100A output is investigated.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.269-272
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• 1988

This paper introduces a method to reduce the reactive power required by electronic converters. The instantaeous reactive power is calculated and compensated by the current controlled PWH voltage source converter connected parallel between the power lines and the converter. A high performance current control technique which is based on the current deviation vector is used for the PWM converter as compensator of reactive power. Accurate compensation of the reactive power and t control system ensuring fast response to the sudden change of loaf are attained. The converter structure and control scheme are discussed. Simulation of the system is performed.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.1
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• pp.47-52
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• 2017

Inductor in high power converter system increases production cost, volume and core loss proportional to the power. To decrease these disadvantages, this paper analyzed the characteristic of parallel-inductor and coupled-inductor in interleaved system with simulation. As a result, it is confirmed that two-phase interleaved non-coupled buck-converter has the best characteristic among three types converter.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.614-617
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• 1999

To achieve high efficiency in high power and high frequency applications, reduction of switching losses and noise is very important. In this paper, an improved zero voltage switching forward dc/dc converter is proposed. The proposed converter is constructed by using energy recovery snubbers in parallel with the main switches and output diodes of the conventional forward dc/dc converter. Due to the use of the energy recovery snubbers in the primary and secondary side, the proposed converter achieves zero-voltage-switching turn-off without switching losses for switching devices and output rectification diodes. The complete operating principles and experimental results will be presented.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.4
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• pp.216-223
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• 2006

In this paper, a methodology for the efficiency improvement of the photovoltaic system without adding some elements or increasing the cost comparing with the conventional system is discussed. It is suggested the optimal photovoltaic module configuration through its performance analysis, and also the suitable maximum power point tracking (MPPT) voltage considered the system cost and the efficiency of the converter. The high efficiency photovoltaic system by using the parallel power transfer (PPT) based MPPT converter is proposed and analyzed theoretically comparing with the conventional Buck type MPPT converter. Finally, it is designed and implemented the proposed photovoltaic system for supplying DC 48V by using the PPT based MPPT converter. And the effect of the efficiency improvement and the usefulness of the proposed system is proved through some preliminary simulation and experiment results.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2695-2697
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• 1999

A new three-phase voltage-fed inverter using partial resonant converter with high power factor and high efficiency is proposed. The proposed Flyback converter is constructed by using a resonant network in parallel with the switch of the conventional converter. The devices are switched zero voltage or zero current eliminating the switching loss. This paper introduces elimination of harmonics compared with conventional SPWM inverter and three-phase voltage-fed inverter using Flyback converter.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.879-880
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• 2008

At the high speed operation, the boost negative bias can reduce the negative torque and increase the dwell angle, so the output power and efficiency can be improved. In this paper, a novel power converter for single phase SRM with boost negative bias is proposed. A simple passive capacitor circuit is added in the front-end, which consists of three diodes and one capacitor. Based on this passive capacitor network, the two capacitors can be connected in series and parallel in different condition. In proposed converter, the phase winding of SRM obtains general dc-link voltage in excitation mode and the double dc-link voltage in demagnetization mode. The operation modes of the proposed converter are analyzed in detail. Some computer simulation and experimental results are done to verify the performance of proposed converter.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.790-796
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• 1998

A novel mode of parallel operation of a modular 3-phase AC-DC flyback converter for power factor correction along with tight regulation was recently analyzed and presented. The advantage of the proposed converter does not require expensive high voltage and high current devices that are normally needed in popular boost type 3-phase converter. In this paper the detailed small signal analysis of the modular 3-phase AC-DC flyback converter is provided for control purposes and also experimental results are included to confirm the validity of the analysis.