• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.15-22
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• 2009

In this paper, a sensorless control of PMSG(Permanent Magnet Synchronous Generator) for small wind turbine systems, which is based on stator flux and back-emf estimation. Also, a cost-effective AE/DC/AC converter that consists of a two-leg three-phase PWM converter and a half-bridge PWM converter is used for vector control of PMSG, which is impossible with the conventional diode-rectifier type converter. A sensorless control algorithm can eliminate pulse encoders for speed measurement, which reduces the system cost. Using PSIM simulation, the validity of the converter control performance and MPPT control of PMSG have been verified.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.4
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• pp.81-94
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• 2010

This paper presents a high efficiency resonant asymmetrical half-bridge flyback converter. The primary half-bridge circuit of the converter operates by a soft-switching type using the asymmetrical pulse-width modulation (PWM) method with the resonant capacitance and transformer leakage inductance. The secondary flyback circuit of the proposed converter utilizes a synchronous rectifier, which operates by a new voltage-driven method with a simple drive circuit. Thus the proposed converter improves the total efficiency. This paper explains the operational principle of the proposed converter by each mode and shows the converter design consideration and a design example for the prototype converter, respectively. After that, the proposed simple driving technique of the synchronous rectifier by a voltage-driven method is explained, briefly. The designed prototype converter has wide input voltage (AC $V_{in,rms}$=75~265[V]), 5[V] DC output voltage, and 100[W] output power. To verify the excellent performance of the proposed converter, the designed prototype is implemented and experimented. The good performance of the proposed converter is shown through the experimental results.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.400-409
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• 1997

Design of single stage AC/DC converter with high power factor and high efficiency based on half-bridge topology for low power application is proposed. To obtain design equations, modelling and detailed analysis are performed. The proposed converter gives and power factor and high efficiency by employing aynchronous rectifiers. To verify the performances of the proposed converter 90W-converter has been designed. This prototype converter meets IEC555-2 requirements with near unity power factor.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.124-128
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• 2001

In this paper, a high-efficiency double-ended active clamp ZVS forward converter is proposed. This converter can be used in compact size AC/DC converter applications such as a notebook adapter. The principles of operation are described and the zero voltage switching characteristics are analyzed. High efficiency of this converter is verified by the experimental results.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.145-149
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• 2000

A single-stage power factor correction AC/DC converter with a simple link voltage suppressing circuit (LVSC) for the universal line application is proposed. Using this simple circuit a low link voltage can be realized without deadbands at line zero-crossings. The proposed converter is analyzed and a prototype converter with 5C, 12V output is implemented to verify the performance. The experimental results show that the link voltage stress and efficiency are about 447V and 81%, respectively.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.260-264
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• 2004

In this paper the novel converter topology for the switched reluctance motor drives is proposed, which is composed of the minimum switch per phase and is connected to the single-phase voltage inverter for ac voltage source. The proposed converter topology is divided into two types according to the voltage source inverter of half bridge type and full bridge type. Proposed converters of two types are proposed, analyzed and compared with each other. The SRM using proposed converter maintain the hi인 efficiency though the power switches are reduced.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.99-100
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• 2014

전압형 HVDC(High Voltage Direct Current)는 현재 차세대 전력망으로써 각광을 받고 있고 그에 대한 연구가 활발하게 진행 중이다. 많은 논문에서 모듈형 멀티레벨 컨버터(Modular Multilevel Converter, MMC)의 제어 및 보호 방안에 대하여 기술하지만 운영적인 시퀀스 측면에 있어서는 아직 많은 연구가 진행되지 않고 있다. 이에 본 논문은 전압형 HVDC의 AC Yard, DC Yard 및 상위 제어기에 관한 구동 시퀀스에 대하여 기술하고자 한다.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.684-687
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• 1999

In this paper, a method for controlling a single phase PWM AC/DC converter without any voltage sensors is proposed. In this method, the source voltage is estimated by sliding mode observer and input current is synchronized with the estimated source voltage. The source voltage is estimated by current error between the actul and the estimated current. The experimental results confirm the validity of the proposed control method.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.97-100
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• 1999

AC to DC single phase PWM converter for traction application requires rated high power and voltage. Therefor, series or parallel operation converters are necessary with considering the limitation of the power device specification. This paper compares the characteristic between two parallel operation of conventional PWM converter and Single phase three level converter about comparison of power circuit, cooling system control method and harmonic current by computer simulation.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.485-488
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• 1999

In this paper, a current control system for single phase PWM AC/DC converter without the source voltage sensors is proposed. The sinusoidal input current and unity effective power factor are realised based on the estimated source voltage in the controller. The estimation of source voltage is performed by the reduced-order Luenberger observer using actual currents. The estimated source voltage is used to accomplish unity power factor. The proposed method is proved by experiments.