• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권8호
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• pp.377-386
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• 2005

This paper presents the control algorithm of single-phase hybrid active power filter for the compensation of harmonic current components in nonlinear R-L load with passive active Power filters. To construct two phase system, an imaginary second phase was made. In this proposed method, the new signal which is the delayed through the filtering by the phase-delay property of low-pass filter is used as the secondary phase. Because two-phases have the different phase, the instantaneous calculation of harmonic current is possible. In this paper, a reference voltage is created by multiplying the coefficient k by the compensation current using the rotating reference frame synchronized with the source-frequency, not applying to instantaneous reactive power theory which has been used with the existing fixed reference frames In order to verify the validities of the proposed control methods, experiments are carried out with the prototypes of single-phase hybrid active power filter.

• 전기학회논문지
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• 제57권5호
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• pp.789-796
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• 2008

This paper describes a single-phase active power filter based on a newly developed digital controller. The developed controller utilizes FFT(Fast Fourier Transform) algorithm to extract the reference signal from the load current, considering the phase-angle delay of each order of harmonics. Optimized technique was applied for whole control algorithm to implement the real-time operation of developed controller. The performance of developed controller for a single-phase active power filter was verified through computer simulations with PSCAD/EMTDC. The feasibility of hardware implementation was confirmed by building and testing a prototype. The developed digital controller for a single-phase active power filter can compensate the harmonic current generated by the power supply for digital equipment.

• Journal of Power Electronics
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• 제9권5호
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• pp.718-725
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• 2009

To get instantaneous reference data in a single power system with vector space phasors, the instantaneous load current is adopted as a phase and another new signal, which is delayed through filtering by the phase-delay property of a low-pass filter, is used as the secondary phase. Because the two-phases have a different phase, the instantaneous value of the harmonic current can be obtained without a time-delay in calculation. The reference voltage is created by multiplying the coefficient k by the compensation current using the rotating reference frame synchronized with the source-frequency. To verify the validity of the proposed control method, experiments are carried out on a prototype of the single-phase hybrid active power filter system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.149-151
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• 2005

This paper deals with the novel control algorithm of single-phase hybrid active power filter for the compensation of harmonic current components in nonlinear R-L load with passive active power filters. To construct two-axes coordinate, an imaginary second phase was made by giving time delay to line current. In this proposed method, the new signal, which was the delayed through the filtering by the phase-delay property of low-pass filter, is used as the secondary phase. Because two phases have different phase, instantaneous calculation of harmonic current is possible. In this paper, a reference voltage is created by multiplying gain of filter by compensation current using the rotating reference frames that synchronizes with source-frequency, not applying to instantaneous reactive power theory which has been used with the existing fixed reference frames. This paper shows the experimental results, which provide a high accuracy and extremely fast response of single-phase hybrid active Bower filter under the operation with the proposed control method.

• 한국철도학회논문집
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• 제7권3호
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• pp.173-179
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• 2004

This paper describes a low-cost single-phase active power filter, which consists of a half-bridge PWM inverter with a simple control circuit. In order to verify the performance of proposed active power filter, many computer simulations with EMTP codes and experimental works with a hardware prototype were done. Both results confirm that the proposed active power filter shows excellent performance to eliminate the harmonics generated in the single-phase non-linear load. The active power filter has advantage of low implementation cost and compact size, using a half-bridge inverter and a simple control circuit with only one current sensor. So, it can be fabricated as a plug-in type. This paper shows the necessity and a good possibility to apply such advantage to the electric railway system.

• 전자공학회논문지
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• 제51권6호
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• pp.271-275
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• 2014

회전하는 동기 좌표계 d-q 변환을 이용한 단상 능동 전력 필터의 새로운 제어기를 제안하였다. 힐버트 변환기를 사용하여 $90{\circ}$의 위상차를 가지는 두 개의 교류 신호를 만든다. 이 신호들을 회전하는 동기 좌표계 d-q 변환을 이용하여 기본파 성분을 직류로 변환할 수 있고 따라서 고조파 검출이 용이하다. 순시 유효 전력의 평균값을 구한다. 역률 보상을 하므로 전원 전류는 전원 전압과 동위상이다. 단상에서의 전력 공식으로부터 전원 전류의 크기를 알 수 있다. 능동 전력 필터의 보상 전류의 기준 신호는 전원 전류의 기준신호에서 부하 전류를 빼주면 구할 수 있다. 새롭게 제안된 제어기에 히스테리시스 전류 제어기를 적용하여 시뮬레이션 하였다. 능동 전력 필터가 부하전류의 고조파와 무효전력을 보상하여 전원 전류가 전원전압과 동위상이 되고 전원전류가 정현파에 가깝게 되는 것을 확인하였다. 힐버트 변환기는 전대역 여파기를 사용하여 구현하였다.

• Journal of Electrical Engineering and Technology
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• 제3권1호
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• pp.94-100
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• 2008

This paper presents a new control method of single-phase active power filter (APF) for the compensation of harmonic current components in nonlinear loads. To facilitate the possibility of complex calculation for harmonic current detection of the single phase, a single-phase system that has two phases was constructed by including an imaginary second-phase giving time delay to the load current. The imaginary phase, which lagged the load current T/4 (Here T is the fundamental cycle) is used in the conventional method. But in this proposed method, the new signal as the second phase is delayed by the filter. Because this control method is applied to a single-phase system, an instantaneous calculation was developed by using the rotating reference frames synchronized to source-frequency rather than by applying instantaneous reactive power theory that uses the conventional fixed reference frames. The control scheme of single-phase APF for the current source with R-L loads is applied to a laboratory prototype to verify the proposed control method.

• Journal of Power Electronics
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• 제12권3호
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• pp.458-467
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• 2012

Single phase converters suffer from ripple power pulsating at twice the line frequency. The ripple power is usually absorbed by a bulky capacitor bank and/or a dedicative LC resonant link, resulting in a low power density and a high cost. An alternative solution is using a dc link active power filter (APF) to direct the pulsating power into another energy-storage component. The main dc link filter capacitor can then be reduced substantially. Based on a mainstream dc APF topology, this paper proposed a new control strategy incorporating both dual-loop control and repetitive control. The circuit parameter design is also re-examined from a control point of view. The proposed APF scheme has better control performance, and is more suited for high power applications since it works in CCM and with a low switching frequency.

• Journal of Power Electronics
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• 제10권4호
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• pp.412-418
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• 2010

This paper proposes a new algorithm to generate a reference signal for an active power filter using a sliding-window FFT operation to improve the steady-state performance of the active power filter. In the proposed algorithm the sliding-window FFT operation is applied to the load current to generate the reference value for the compensating current. The magnitude and phase-angle for each order of harmonics are respectively averaged for 14 periods. Furthermore, the phase-angle delay for each order of harmonics passing through the controller is corrected in advance to improve the compensation performance. The steady-state and transient performance of the proposed algorithm was verified through computer simulations and experimental work with a hardware prototype. A single-phase active power filter with the proposed algorithm can offer a reduction in THD from 75% to 4% when it is applied to a non-linear load composed of a diode bridge and a RC circuit. The active power filter with the proposed reference generation method shows accurate harmonic compensation performance compared with previously developed methods, in which the THD of source current is higher than 5%.

• 전력전자학회논문지
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• 제4권4호
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• pp.342-348
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• 1999

본 논문에서는 간단한 제어회로와 반브릿지 PWM 인버터로 구성된 저가의 단상능동전력필터에 대해 기술하고 있다. 이 능동전력필터의 성능을 확인하기 위하여 EMTP 프로그램에 의한 시뮬레이션을 실시하고 프로토타입을 제작하여 실험을 실시하였는데, 그 결과 제안하는 능동전력필터는 단상비선형부하가 발생하는 고조파를 제거하는데 우수한 성능을 갖고 있음을 확인할 수 있었다. 제안된 시스템은 반브릿지 인버터와 단일 전류센서를 사용한 간단한 제어회로로 구성되었기 때문에, 하드웨어 비용이 저렴하고 프러그인 타입으로 제작 가능한 장점을 갖는다.