Fault-Tolerant Control Under Open-Circuit Faults Based on Four-Leg Power Converter for Doubly Salient Reluctance Machine

In this article, the fault-tolerant control under open-circuit faults based on four-leg power converter for doubly salient reluctance machine (DSRM) is presented. First, the mathematical model of the DSRM is built, and the normal operation mode is analyzed. Then, three fault-tolerant control modes are proposed according to the locations of the open-circuit faulty switches. When the faulty switches belong to groups 1 or 2, the multiple current chopping control (CCC) modes are adopted, respectively. When the faulty switches belong to group 3, the sinusoidal current without dc-bias control mode is employed. To reduce the torque fluctuation when the DSRM is switched from normal mode to fault-tolerant mode, the torque and current relationships between different control modes are analyzed. Then, the overall control scheme and smooth switching control strategy for different fault-tolerant modes are proposed. Finally, a three-phase 12/10 DSRM experimental platform is built, and the experiments are carried out to verify the effectiveness of the proposed fault-tolerant control method.