COMPARATIVE PERFORMANCE EVALUATION OF DIFFERENT TOPOLOGIES OF HYBRID POWER FILTERS

Abstract

Industrial, Commercial and Residential usage of induction motors and nonlinear power electronic loads like thyristor rectifiers and variable speed ac drives draw reactive power and harmonic components of currents from the utility, thereby deteriorating the power quality. The proliferation of these harmonic producing equipments led to the increase in research leading to improved understanding of harmonic problem, methods and techniques for studying it, and approaches for mitigating unacceptably high levels of distortion. Passive Filters are one such device for harmonic compensation which employs a combination of Inductors and Capacitors. However there are several limitations of using Passive filters and this has led to the development of Active Filters which can provide harmonic compensation dynamically. Hybrid Filters, a combination of passive and active filters, is another such approach that improves compensation characteristics of both passive and active filters used alone, by keeping the advantages of both the filters. The following work aims at understanding the various problems of harmonics, the devices that compensate these harmonics, their advantages and disadvantages, their design procedures, various control strategies associated with active filters, and the comparative evaluation of passive, active and a few topologies of hybrid filters using MATLAB/SIMULINK. An experimental prototype of Shunt Active Filter is implemented in hardware and results are verified.