An Embedded Fault-Tolerant Control Method for Single Open-Switch Faults in Standard PMSM Drives

Permanent magnet synchronous motor (PMSM) and its drive have been widely employed in many industrial sectors. However, the standard PMSM drive has limited fault-tolerant capability compared to other complex drive topologies. In this article, to improve its postfault drivability under open-switch faults, an embedded fault-tolerant control method is proposed. The proposed method comprises three parts: First, based on the mathematical analysis of the postfault voltage vectors, a reallocation strategy for the vector acting time calculated by space vector pulse width modulation is proposed to track the healthy reference vector. Besides, to track the currents under the fault conditions, a current prediction model based on the acting time and voltage excitations of the active vectors is proposed. Furthermore, to guarantee an accurate transition of the postfault current control under the health conditions and the fault conditions, a transition-enabling mechanism is designed based on the residuals between the normal prediction model and the proposed prediction model. Finally, the effectiveness of the proposed method is validated by simulations and experiments.