An induction motor drive system with improved fault tolerance

Abstract

This paper investigates the utilization of a low cost topology that permits the fault-tolerant operation of a three-phase induction motor drive system. When one of the inverter legs is lost, the machine can operate with only two stator windings by connecting the machine neutral either to the middle point of a capacitor bank or to a fourth converter leg. The structure proposed and the operation principle of the system are presented. The machine model corresponding to the asymmetric two-windings machine is developed and a suitable controller is proposed. Experimental results are presented.