Resilient current control of five-phase induction motor under asymmetrical fault conditions

Abstract

This paper presents the resilient current control of a five-phase induction motor under asymmetrical fault conditions. This kind of control scheme ensures that the five-phase induction motor operates continuously and steadily without additional hardware connections in case of loss of up to two phases, which is of importance to some specific applications where fault tolerance and high reliability are required. The five-phase induction motor proposed adopts the concentrated winding structure and makes use of the third harmonic currents to generate the nearly rectangular flux distribution in the air gap resulting in improvement of flux density and increase of output torque. Under asymmetrical fault conditions, the proper third harmonic currents are still superimposed on the fundamental currents of the five-phase induction motor with the remaining phases so as to maintain a nearly rectangular air-gap flux similar to the symmetrical conditions. Consequently, the five-phase induction motor can still produce improved flux density and increased output torque. Simulation analysis and experimental verifications on the resilient current control of the five-phase induction motor under the symmetrical and asymmetrical conditions are included in this paper.