Fault-Tolerant Control of Hybrid Excitation Axial Field Flux-Switching Permanent Magnet Machines

Abstract

With the development of electric vehicles (EVs), the reliability and security of the motor drive system have been in high demand in recent years. EVs can still work reliably even when the motor drive system encounters some failures. Therefore, fault-tolerant motors have become the focus of research all over the world. The hybrid excitation axial field flux-switching permanent magnet machine (HEAFFSPMM) is a novel stator excitation brushless PM machine. It combines the advantages of AFFSPMM and hybrid excitation PM machine. Based on a 600 W prototype of three-phase 12/10 stator/rotor pole AFFSPMM, these parameters of HEAFFSPMM are optimized by 3-D finite element method in order to obtain the high self-inductance and low ratio of mutual and self-inductances, including the number of rotor poles, the split ratio, the width of permanent magnet, and the width of stator middle teeth. Then, the fault-tolerant control method of the space vector pulse width modulation based on minimum copper loss is proposed in this paper with the combination of adjusting the field current. The control methods of the HEAFFSPMM are simulated and investigated at healthy and one-phase open-circuit operation. Finally, the experiments are done to validate the proposed fault-tolerant control method. The results indicate that the HEAFFSPMM has good fault tolerance under the proposed control method.