Design and Implementation of Hybrid Active Power Filters For Power Quality Improvement in Industries

This paper presents design and simulation of a three-phase hybrid active power filter to eliminate the harmonics and for mitigation of the power quality problem at ac mains in ac-dc power supply feeding to a nonlinear load. The non linear loads take discontinuous current and thus it injects harmonics. The hybrid active power filter, which combines active power filter, passive power filter and generalized integrators, and which has their both respective merits, leading the development of electric reliability and quality. This harmonic distortion can be reduced by suppressing the harmonic resonance using the hybrid active filter, which is operated as variable harmonic conductance according to the voltage total harmonic distortion. Therefore, the harmonic resonance would be avoided as well as harmonic voltage distortion can be maintained at an allowable level. Finally, representative simulation results of a three phase hybrid active filter are presented to verify the effectivemess of HAPF in power quality enhancement.