Fault-Tolerant Control Strategy of Open-Winding Permanent Magnet Synchronous Motor with Common DC Bus Under Switch Open-Circuit Fault

In order to further improve the operation performance of the open-winding permanent magnet synchronous motor (OW-PMSM) with common DC bus under switch open-circuit fault, a fault-tolerant control strategy based on the unipolar control of the fault phase current is proposed. Firstly, based on the detailed analysis of the output voltage and current characteristics of the fault phase after switch fault, a fault-tolerant pulse width modulation (FTPWM) is proposed. Under this modulation method, the fault phase current can maintain unipolar flow, thus ensuring the correct output of the phase voltage. Secondly, the output performance of the motor under fault-tolerant control is evaluated. After the fault, the motor still has a wide speed range and high load capacity. By analyzing the detailed torque equation of the OW-PMSM, it is proved that the motor can still output stable torque after the fault. Finally, the proposed fault-tolerant control strategy is simulated and verified in MATLAB. Theoretical analysis and simulation results verify the feasibility of the fault-tolerant scheme.