Fault-Tolerant Control Strategies of Five-Phase Induction Motor Drives under Open-Switch Fault

When an open switch fault occurs, a power switch in a converter leg is always open while the corresponding freewheeling diode can still conduct. This type of fault is usually caused by some problems in the driver circuits or the PWM communication system.An open-switch fault is usually treated as an open-phase fault, but new control strategies with improved performance can be developed specifically for this type of fault.In this paper, four different control strategies against an open switch fault are presented and compared in terms of stator Joule losses and torque ripple. A motor control scheme for multiphase induction motor drives is developed and assessed.The feasibility of the proposed solution is verified by means of experimental tests on a prototype of five-phase induction motor.