• 전력전자학회논문지
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• 제9권2호
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• pp.126-133
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• 2004

본 연구에서는 저 비용 응용분야에 적합한 4스위치 3상 BLDC 전동기의 새로운 전류 제어 알고리즘을 제안하였다. 4스위치 시스템에서 빠른 속도 및 토크 응답 그리고 적은 토크 리플과 같은 좋은 동작 특성을 얻기 위한 기준 전류 발생 기법을 제안하였다. 특히, 제안한 기법은 전류 전환시 발생되는 토크 리플을 현저히 저감시켜 4스위치 시스템을 산업 응용 분야에 보다 널리 적용할 수 있을 것으로 기대한다.

• Journal of Power Electronics
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• 제3권4호
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• pp.249-258
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• 2003

This paper presents a high-efficient and cost effective three-phase AC/DC-DC/AC power conversion system with a single two-switch type active Auxiliary Resonant DC Link (ARDCL) snubber circuit, which can minimize the total power dissipation. The active ARDCL snubber circuit is proposed in this paper and its unique features are described. Its operation principle in steady-state is discussed for the three phase AC/DC-DC/AC converter, which is composed of PWM rectifier as power factor correction (PFC) converter, sinewave PWM inverter. In the presented power converter system not only three-phase AC/DC PWM rectifier but also three-phase DC/AC inverter can achieve the stable ZVS commutation for all the power semiconductor devices. It is proved that the proposed three-phase AC/DC-DC/AC converter system is more effective and acceptable than the previous from the cost viewpoint and high efficient consideration. In addition, the proposed two-switch type active auxiliary ARDCL snubber circuit can reduce the peak value of the resonant inductor injection current in order to maximize total system actual efficiency by using the improved DSP based control scheme. Moreover the proposed active auxiliary two-switch ARDCL snubber circuit has the merit so that there is no need to use any sensing devices to detect the voltage and current in the ARDCL sunbber circuit for realizing soft-switching operation. This three-phase AC/DC-DC/AC converter system developed for UPS can achieve the 1.8% higher efficiency and 20dB lower conduction noise than those of the conventional three-phase hard-switching PWM AC/DC-DC/AC converter system. It is proved that actual efficiency of the proposed three-phase AC/DC-DC/AC converter system operating under a condition of soft switching is 88.7% under 10kw output power.

• 전기학회논문지P
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• 제58권3호
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• pp.303-309
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• 2009

Switched Reluctance Motor(SRM) has become popular for industrial application, particularly for low medium drives due to the advantages of SRM over the other ac motors: SRM can be manufactured with low cost because it has a simple structure. But, asymmetric bridge converter that generally is used for driving requires two discrete switching devices and freewheeling diodes per phase, and cause the SRM drives to be complicated and to increase the cost of overall system. Therefore, this paper suggests a new type of 4-switch converter for SRM. 4-switch converter topology is studied to provide a possibility for the realization of low cost 3-phase SRM drive system. For effective utilization of the developed system, a new current control algorithm is designed and implemented to produce the desired dynamic performance. With the developed power conversion circuit and control scheme, it is expected that the proposed system can be widely used in commercial applications with reduced system cost.

• 전력전자학회논문지
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• 제5권6호
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• pp.523-529
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• 2000

• 전력전자학회논문지
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• 제16권6호
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• pp.561-568
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• 2011

본 논문은 단상 이중변환 무정전전원장치를 위한 단일 스위치 배전압 방식의 단상 PFC 컨버터의 동작 특성을 기술한다. 단일 스위치 배전압 방식의 단상 PFC 컨버터는 브릿지 다이오드와 양방향 능동 스위치 한 개만이 필요하며 재료비 절감이 가능하다. 하지만 이 회로가 제안된 후 동작 특성 및 제어기 설계에 대한 연구결과가 알려지지 않았다. 본 논문에서는 동작 특성과 제어기 설계방법을 기술하고 성능평가를 위해 단상 정격 3kVA 이중변환 무정전전원장치를 대상으로 실험을 수행하였다. 또한 실험을 통해 입력전류 제어, 입력역률 보상 성능을 확인하였다.

• 전력전자학회논문지
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• 제17권1호
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• pp.1-7
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• 2012

This paper describes the performance comparison results for current controller of a single-phase PFC converter with 1-switch voltage doubler strategy for single-phase double-conversion UPS(Uninterruptible Power Supply). A single-phase PFC converter with 1-switch voltage doubler strategy needs a diode bridge and one bidirectional active switch. Thus it is possible to reduce the material cost. However, the study results of current controller design and comparison of current control method has not been known after the converter circuit was proposed. For the performance comparison of current control, single-phase 3 kVA double-conversion UPS was tested. The performance of PI and PR current controller is experimentally confirmed with followings - input current reference tracking, input power factor correction and input current THD suppression.

• Journal of Power Electronics
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• 제18권5호
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• pp.1501-1512
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• 2018

This paper proposes a three-phase three-switch buck-type converter as the MSC of a wind turbine system. Owing to a novel switching modulation scheme that can eliminate the unwanted diode rectifier mode switching state, the proposed system exhibits a satisfying ac voltage and current waveform quality and torque ripple up to the level of a typical current source rectifier even under a wide power factor operating range. The proposed system has been verified through simulations and HILS tests on a PMSG wind turbine model of 5MW/4160V. The proposed converter has been shown to provide a stator current THD of 3.9% and a torque ripple of 1% under the rated power condition. In addition to the inherent advantage of the reduced switch count of three-phase three-switch buck-type converters, the proposed switching modulation technique can make this converter a viable solution for the MSC placed inside of a nacelle, which is under severe volume, weight and mechanical vibration design limits.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.275-276
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• 2013

In this paper, we proposed the Z-source four-switch three-phase rectifier. As we know, the conventional Four-Switch Three-Phase Rectifier(FSTPR) has advantages of the lower cost and less complex switching control. However, The conventional FSTPR can only either perform buck or boost operation, it can only attain the buck-boost operation by adding another DC-DC converter. In addition, besides its narrow output voltage region, distortion of the input current is serious either. Thus, we proposed the Z-source FSTPR which has buck-boost function and better input current waveform by applying the Z-impedance network to the conventional FSTPR. The validity of the proposed system was confirmed by experiments.

• 전기학회논문지
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• 제58권11호
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• pp.2162-2167
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• 2009

A Low cost and variable speed brushless motor drive system with single switch per phase is presented. The motor drive is realized with a novel two-phase flux-reversal-free switched reluctance motor and a split AC two switch converter. The strategy of the controller and the converter for its realization are described. Comparisons between a split AC converter, asymmetric converter, split DC converter, single controllable switch converter, and N+1 converter are performed for its device rating, cost, switching losses and conduction losses, and converter efficiency. The split AC converter is analyzed and simulated to verify the characteristics of the converter circuitry and control feasibility and the simulation results are presented. The efficiency with various loads is numerically estimated and experimentally compared from viewpoint of subsystem and system in details. The focus of this paper is to compare the presented motor drive system to the asymmetric converter system throughout experiments and demonstrate single switch per phase converter having comparable efficiency as the asymmetric converter system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.216-218
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• 2008

This paper presents a space vector pulse width modulation (SVPWM) technique for four-switch three-phase (4S3P) inverter topology. The method aims to apply Field Oriented Control (FOC) of Induction motor using 4S3P. The simulations are carried out and the experimental results are given to verify the feasibility of this method.