Third Harmonic Current Injection for Power Quality Improvement in Rectifier Loads

This paper presents a novel method of reducing harmonic currents at the point of common coupling (PCC) in a three-phase diode bridge rectifier type utility interface. The proposed configuration consists of a current injection device, a newly designed current injection network and a properly tuned passive shunt filter. It also presents the design details of the current injection network and the passive filter. The proposed configuration performs well under varying loads on the rectifier. The effect of load variation on rectifier is also studied to demonstrate the effectiveness of the proposed ac-dc converter. A set of power quality indices on input ac mains and on dc bus is also presented and discussed in detail.