Optimized OP-FTC for SPMSM Considering Copper Loss Minimization

The traditional fault-tolerant control (FTC) strategy can guarantee that permanent magnet synchronous machine (PMSM) operate stably in open-phase fault (OPF) situation. However, the copper loss minimization is usually out of consideration. Therefore, an optimized open-phase FTC (OP-FTC) method is put forward for surface-mounted PMSM (SPMSM) considering copper loss minimization. First, when an OPF happens, according to the theory that magneto-motive force remains unchanged in normal and faulty situations, the relationships between the remaining two-phase currents and the dq-axis currents are obtained to make SPMSM output the same torque as that before the fault appearance. Then, based on the relationship between dq-axis currents and copper loss, the d-axis current is calculated to make copper loss minimum. Finally, the proposed OP-FTC strategy is presented for SPMSM drive system. The simulation and experiment are studied to test the optimized OP-FTC strategy.