Fault-Tolerant Control of Open-phase Fault For sensorless PMSM Drives

In this paper, to improve the postfault of the sensorless permanent magnet synchronous machine (PMSM) drives, a novel fault-tolerant control method for open-phase fault (OPF) is proposed to considering the current commutation based on the new rotor position estimation. In the proposed method, the estimation of the rotor position is diverse in normal and OPF operation by using the NO. After OPF, the stator voltages are calculated to replace the voltage inputs of NO, which can estimate the rotor position correctly in OPF operation. Therefore, the estimated rotor position is still used to ensure the safety operation of PMSM drive in OPF fault-tolerant operation. Meanwhile, the current reference is optimized considering the current endurance and electromagnetic torque ripple. By replacing the normal d-axis and q-axis current references with the optimized current references, the negative electromagnetic torque is eliminated significantly, and the current tracking errors is reduced. Finally, the advantages and the improved postfault performance of sensorless PMSM drive has been validated by simulation results.