Multilevel Inverter Scheme With Inherent Common-Mode Voltage Elimination and DC-Link Capacitor Voltage Balancing for Open-End Winding Induction Motor Drive

Abstract

A multilevel inverter scheme for an open-end winding induction motor (IM) drive is proposed to maintain the balance in the dc-link capacitor voltages, and to eliminate the common-mode voltage (CMV), simultaneously. The proposed scheme does not call for any extra control hardware for the capacitor voltage balancing. Performance of the drive is verified in both the directions of rotation in the motoring as well as in the regenerating mode of operation. The control scheme is simulated and experimentally verified on a 1.5 kW open-end winding IM drive. It is shown that the proposed scheme is inherently capable of eliminating the CMV, and at the same time maintains the voltage balance in all the four capacitors of the dc-link, throughout the operating range of the drive.