• 전기전자학회논문지
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• 제23권2호
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• pp.495-501
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• 2019

본 논문에서는 정류 브리지 다이오드를 갖는 단상 무정전전원장치의 전원측 고조파 및 역률 개선을 위한 가변형 고조파 필터를 제안한다. 2레벨 이상의 전력변환방식을 적용한 무정전전원장치는 전원측 고조파 및 역률 특성이 우수한 반면, 전 브리지 방식의 무정전전원장치는 전원측에 제 3고조파, 제 5고조파, 제 7고조파 및 역률 저하를 심각하게 야기한다. 이에 따라 단상 전 브리지 동작에 의해 야기된 (2n+1)차 고조파 제거 및 역률 개선을 위한 가변형 고조파 필터를 제안하고자 한다. 제안한 가변형 고조파 필터의 성능을 평가하기 위해 다양한 시뮬레이션과 실험을 진행하여 타당성을 검증하였다.

• Journal of Power Electronics
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• 제10권5호
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• pp.563-571
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• 2010

A model of an advanced aircraft electric power system is developed and studied under variable-speed constant-frequency (VSCF) operation. The frequency of the generator's output voltage is varied from 400-Hz to 800-Hz for different loading scenarios. Power conversions are obtained using 12-pulse power converters. To reduce the harmonic contents of the generator output waveforms, two high-pass passive filters are designed and installed one at a time at the generator terminals. The performance of the two passive filters is compared according to their losses and effectiveness. The power quality characteristics of the studied VSCF aircraft electric power system are presented and the effectiveness of the proposed filter is demonstrated through compliance with the newly published aircraft electrical standards MIL-STD-704F.

• 전기학회논문지
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• 제58권11호
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• pp.2149-2154
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• 2009

Electric power quality in power transmission/distribution systems has considerably been deteriorated with the increase in the capacity of distributed generators (DGs). It is because inverters, connecting DGs to conventional power grids, tend to generate harmonic current and voltage. For harmonic mitigation, a large amount of research has been done on passive and active filters, which have been operating successfully in many countries. This paper, therefore, presents how to adopt the filters to an inverter-based DG, with considering a system consisting of both inverter-based DG and harmonic filters. In particular, this paper describes the simulation results using the PSCAD/EMTDC: firstly, the relationship between total harmonic distortion(THD) of current and output power of DG: secondly, the harmonic mitigation ability of passive and active filters. The system, furthermore, is obliged to satisfy the regulations made by Korean Electric Power Corporation(KEPCO). In the regulations, power factor should be maintained between 0.9 and 1 in a grid-connected mode. Thus, this paper suggests two methods for the system to control its power factor. First, the inverter of DG should control power factor rather than an active filter because it brings dramatic decrease in the capacity of the active filter. Second, DG should absorb reactive power only in the range of low output power in order to prevent useless capacity increase of the inverter. This method is expected to result in the variable power factor of the system according to its output power.

• 대한전자공학회논문지TC
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• 제46권9호
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• pp.46-51
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• 2009

본 논문에서는 고 효율 인덕터 특성이 저역 통과 필터의 고조파 성분 억제에 미치는 정량적인 영향에 관한 새로운 접근 방안을 제안한다. 적용될 고 효율 인덕터의 정확한 소자 값들을 추출하기 위해 신뢰성 있는 De-embedding 과정을 적용 하였다. 게다가, 이들의 효과적인 적용 및 비교를 위해, 같은 스펙을 갖는 다양한 계단 임피던스 저역 통과 필터들을 각각 설계하였다. 제안된 과정은 전체 필터 성능을 제어하고 정해진 스펙으로부터 합성되는 등가 회로를 구성하기 위해 효과적으로 응용될 것이라 기대된다.