Fault tolerant control method to improve the torque and speed response in PMSM drive with winding faults

Abstract

Fault tolerant operation of motor drives is inevitable in many safety critical applications as failures could lead to complete shutdown or degrade the performance of the whole system. Therefore, it has become important to have fault tolerant capability to support continuous operation. This paper focus on the control of a star connected fault tolerant permanent magnet synchronous motor (PMSM) drive which suffers from open winding fault that may resulted from broken or disconnected stator phase winding. The considered fault tolerant derive has the reconfiguration capability to support open winding faults which connect the neutral point of the motor to the mid point of the dc link. This allows exciting the remaining two windings and supports the fault tolerant operation. One of the main problems of this topology is the high torque and speed ripple generated during the fault mode operation. In this paper, a comprehensive literature review is presented to identify different fault tolerant converters and published control techniques. Then faulty mode operation with standard techniques is re-evaluated and based on the findings a control method is proposed to improve the performance of PMSM drive under open phase fault. Furthermore, a method to detect and diagnose open phase faults and a control method to improve the faulty mode performance are also presented. Proposed control technique is verified in simulation result.