• 전력전자학회논문지
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• 제20권2호
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• pp.182-192
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• 2015

This study develops a digital control scheme with power factor correction for a front-end converter in an electric vehicle battery charger. The front-end converter acts as the boost-type switching-mode rectifier. The converter assumes the two roles of the battery charger, which include power factor control and robust charging performance. The proposed control scheme consists of a charging control algorithm and a grid current control algorithm. The scheme aims to obtain unity input power factor and robust performance. Based on the linear average model of the converter, a constant-current constant-voltage charging control algorithm that passes through only one proportional-integral controller and a current feed-forward path is proposed. In the current control algorithm, we utilized a second band pass filter, a single-phase phase-locked loop technique, and a duty-ratio feed-forward term to control the grid current to be in phase with the grid voltage and achieve pure sinusoidal waveform. Simulations and experiments were conducted to verify the effectiveness of the proposed control scheme, both simulations and experiments.

• 전기학회논문지
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• 제65권5호
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• pp.843-850
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• 2016

In this paper, we propose a digital controller design process for the interleaved type of a boost PFC (Power Factor Correction) converter which can disperse the heat of the switching devices due to the interleaved topology. We establish a mathematical model of a boost PFC converter and propose a controller design method based on the root locus. The performance of the designed controller is verified by simulations. The measurement of the input voltage, inductor currents, and the converter output link voltage are needed for the control of the converter system which consists of a power unit and a control unit where a high-performance 32-bit microcontroller is used. The adjustment of A/D conversion timing is also needed to avoid high frequency noise generated when the switches on/off. It is illustrated by the real experiments that the designed control system with the properly adjusted ADC timing satisfies the given performance specifications of the interleaved boost PFC converter in the on-board slow battery charger.

• 전력전자학회논문지
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• 제3권2호
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• pp.107-117
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• 1998

근래에 들어, 입력 교류전원에서 양질의 전력을 공급하기 위하여 역률 개선 회로에 대한 연구가 활발히 진행되고 있다. 그 중 QBSRR이라는 ZCS(Zero Current Switching) 공진형 역률 개선 회로가 최근에 소개되었는데, 본 논문에서는, QBSRR회로의 전력단에 대하여 간단하고 정확한 모델링을 이용하여 안정된 출력 전압과 빠른 동적특성을 얻기 위한 데드빗(Deadbeat) 제어기를 체계적으로 설계하였다. 또한, 전류 센서를 사용하지 않고 부하 저항값을 파악하기 위하여 부하 예측 기법(Load Estimation Method)을 유도하였다. 본 논문에서는 제안한 제어기를 이용하면, 역률개선 회로의 출력측에 나타나는 120Hz의 리플에도 불구하고 안정된 출력전압과 빠른 동적 특성을 얻을 수 있게 된다. 아울러, 과도 응답 상태에서도 입력측의 높은 역률이 유지되는 장점을 가지고 있다. 시뮬레이션과 실험을 통하여 본 논문에서는 제안한 제어기의 우수한 특성을 입증하였다.

• 전기학회논문지
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• 제66권2호
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• pp.328-338
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• 2017

In this paper, a zero torque control scheme adopting current sharing function (CSF) used in integrated Switched Reluctance Motor (SRM) drive with DC battery charger is proposed. The proposed control scheme is able to achieve the keeping position (KP), zero torque (ZT) and power factor correction (PFC) at the same time with a simple novel current sharing function algorithm. The proposed CSF makes the proper reference for each phase windings of SRM to satisfy the total charging current of the battery with zero torque output to hold still position with power factor correction, and the copper loss minimization during of battery charging is also achieved during this process. Based on these, CSFs can be used without any recalculation of the optimal current at every sampling time. In this proposed integrated battery charger system, the cost effective, volume and weight reduction and power enlargement is realized by function multiplexing of the motor winding and asymmetric SR converter. By using the phase winding as large inductors for charging process, and taking the asymmetric SR converter as an interleaved converter with boost mode operation, the EV can be charged effectively and successfully with minimum integral system. In this integral system, there is a position sliding mode controller used to overcome any uncertainty such as mutual inductance or DC offset current sensor. Power factor correction and voltage adaption are obtained with three-phase buck type converter (or current source rectifier) that is cascaded with conventional SRM, one for wide input and output voltage range. The practicability is validated by the simulation and experimental results by using a laboratory 3-hp SRM setup based on TI TMS320F28335 platform.