Interharmonic analysis and mitigation in adjustable speed drives

This paper presents the theoretical background and studies on the supply side current interharmonics in a double-stage Adjustable Speed Drive (ASD), when they are initiated by motor current imbalance. Some useful approaches are then proposed to compensate for these interharmonic currents in partially and/or fully controlled ASD, resulting in undistorted grid currents. The simulation studies verify the effectiveness of the proposed schemes.