Mitigation of Harmonics and Inter- harmonics in VSI-Fed Adjustable Speed Drives

Abstract – The components of harmonics are integral multiple of the fundamental component and the components of inter-harmonics are are non integral multiple of the fundamental component. AC-DC-AC conversion systems used in variable speed drive are sources of inter-harmonics. There are several reasons for inter-harmonic generation in variable speed drives. In this paper, the generation of inter-harmonics in the supply side due to indirect frequency converter is considered. A passive filter is designed to mitigate harmonics and inter-harmonics. The accuracy of the proposed method is verified using the simulation tool of PSIM. Simulated results of VSI-fed induction motor with the proposed filter prove the effectiveness of mitigation. Keyword — Inter-harmonics, harmonics, adjustable speed drives, passive filter, and series reactor