Fault Tolerant Control Strategy in Open-Winding Drive System with Common Mode Connected DC Buses Based on Instantaneous Power Optimization

As an ideal alternative solution for the drive system of new energy vehicles, the open-winding topology with common mode connected DC buses both possesses the diversity of power source configuration and the advantages of electromagnetic interference and fault tolerance ability. However, once open circuit faults occur in single phase or power devices in the same phase, the remaining healthy phases of the system will automatically be in two-phase operation situation, which causes more loss. In this paper, a fault tolerance control scheme based on instantaneous power optimization is proposed. In this way, the total instantaneous power of the system remains unchanged through a fault occurrence which simultaneously minimizes losses of stator. Besides, the control algorithm allows a steady operation after the implementation of the fault-tolerant scheme without extra hardware components. Finally, the rationality and superiority of the designed control strategy are verified by simulation.