A Nine-Level Inverter for Open Ended Winding Induction Motor Drive with Fault-Tolerance

Abstract

This paper presents a nine level inverter for an open ended winding induction motor (OEWIM) drive with fault tolerance property for switch faults. The proposed topology consists of three three-phase inverters with an isolated DC source for each inverter, three bi-directional switches and three capacitors. The three inverters are configured such that they all have a common neutral connection between them. Such configuration provides the advantage of producing peak output voltage twice the source voltage magnitude and hence lower rating voltage sources can be employed. Conventional sinusoidal pulse width modulation techniques are employed for generating gate pulses for the switches in the proposed topology for normal and post-fault operation. A fault-tolerance strategy is proposed for the post-fault operation of the inverter to produce balanced three phase supply. Simulations are carried out in MATLAB/Simulink environment and results are presented.