سال انتشار: ۱۳۷۸
محل انتشار: پانزدهمین کنفرانس بین المللی برق
تعداد صفحات: ۱۰
Yazdian-Varjani – Dept of Elec., Com Eng. Tarbiat Modares University, Tehran, Iran
Chicharo – School of Elec., Comp & Telecom Eng University of Wollongong, NSW 2522,Australia
Perera – School of Elec., Comp & Telecom Eng University of Wollongong, NSW 2522,Australia
Active power filters are used in power systems not only for harmonic compensation, but also for reactive power compensation and voltage control. This means that the rating of an active filter can be less than that of a passive filter for the same nonlinear load. Also an active filter will not introduce system resonances that can move a harmonic problem from one frequency to another. Harmonic compensation becomes a cost-sensitive issue for customers when utilities start to enforce harmonic standards. Consequently, cost is still seen to be an obstacle for the wide spread deployment of active power filtering (APF). Therefore, the task of choosing a reliable and economical methodology for harmonic reduction from both the industrial end user and utility perspective becomes very important [ 11). A reduction in active power filter rating is desirable while satisfying the minimum requirements set in the harmonic standards. This can be achiev ed by reducing only those harmonies that exceed the acceptable levels recommended by the respective standards. This concept could be implemented by producing an on-line estimation of the load current harmonic components. In this paper a novel control strategy suitable for a shunt active power filter has been presented which includes an on-line phase/frequency tracking, a filter bank based harmonic estimation together with a selective and partial harmonic reduction scheme. A prototype system has been developed and results indicate that the proposed approach not only works well but also provides significant benefits including a reduction of active power filter rating, incorporating of other method into harmonic reduction such as hybrid active and passive filter. The paper is organised as follows: section 1.2 discusses in detail the proposed control strategy for the active power filter. It includes the harmonic estimation, frequency tracking and reference waveform generation. Section 1.3 describes the proposed harmonic reduction schemes including selective and partial reduction schemes. Finally, simulation test are presented and experimental results obtained from an actual prototype APF system is discussed in sections 1.4 and 1.5.