A Hybrid Active Filter for Damping of Harmonic Resonance in Industrial Power Systems

Abstract

Abstract-This paper proposes a hybrid active filter for damping of harmonic resonance in industrial power systems. The hybrid filter consists of a small-rated active filter and a 5th-tuned passive filter. The active filter is characterized by detecting the 5th-harmonic current flowing into the passive filter. It is controlled in such a way as to behave as a negative or positive resistor by adjusting a feedback gain from a negative to positive value, and vice versa. The negative resistor presented by the active filter cancels a positive resistor inherent in the passive filter, so that the hybrid filter acts as an ideal passive filter with infinite quality factor. This significantly improves damping the harmonic resonance, compared with the passive filter used alone. Moreover, the active filter acts as a positive resistor to prevent an excessive harmonic current from flowing into the passive filter. Experimental results obtained from a 20-kW laboratory model verify the viability and effectiveness of the hybrid active filter proposed in this paper.

Series Active Compensation of Current Harmonics Generated by High Power Rectifiers

“…In order to overcome these problems, active power filters have been proposed and analyzed in the technical literature [1]- [4]. The classical shunt active power filter operates as a controlled current source while the series active approach acts as controlled voltage source.…”

“…The dc capacitor value is obtained using (1). With this value, the capacitor is able to store enough energy to supply the instantaneous power required by the ac system during half a cycle without resulting in dc voltage variations of more than 5 %.…”

“…Different compensation techniques based in active and passive filters to eliminate current harmonics and to compensate reactive power have been presented and published [1,2,3]. Shunt, series and hybrid active filter topologies have been discussed and demonstrated to be an effective solution for non-linear load compensation.…”

Hybrid Filters To Damp Harmonic Resonance In Power Transmission Systems

“…At the Ibiúna substation, a pure active filter to solve the problem of the high 5 th order harmonic voltage in the passive filters would not be economically and technically viable because of the high power of the system. A hybrid filter, consisting of an active filter combined with the existent passive filters, would be a less expensive solution, uniting the advantages of both filters [5]- [6].…”

Three-Phase Z-Source Hybrid Active Power Filter System

“…질에 악영향을 끼치고 있다. 이와 같이 전력품질을 개 선하기 위한 효과적인 방법 중의 하나가 능동전력필터 (active power filter) [1][2][3][4][5][6]16,17,27,28] [18][19][20][21]에 잘 설명되어져 있으며, 그림 7에는 7-PF에 대한 보드선도를 나타내었다. 전원단의 Z-AF에서 발생되는 2kHz이상의 스위칭 주파수 성분과 60Hz 기본파 성분은 420Hz 직렬공진 회로인 7-PF에 의하여 저지되고, 비선형 부하에서 발 생되는 7차 고조차 성분에 대해서 7-PF는 낮은 임피 던스를 제공한다 [16,27,28]…”