Design of Fault-Tolerant Control Strategy for Dual-Winding Permanent Magnet Synchronous Motor in Vehicles

Motor drive control is crucial for achieving the performance, reliability, and comfort of electric vehicles. Multi-phase motors, represented by dual-winding permanent magnet synchronous motors (PMSMs), have significant research value in the electric vehicle field due to their high-power drive capabilities and strong fault tolerance. A simple and easily analyzable motor model is essential for achieving high precision in control. This paper employs VSD coordinate transformation (vector space decomposition) based on electromagnetic principles and the positional relationships between windings, treating the multi-phase motor as a whole and mapping various physical quantities to multiple subspaces for simplified analysis. Consequently, a mathematical model for the dual-winding PMSM is established. The vector control system based on VSD coordinate transformation adopts a dual closed-loop structure for speed and current. It focuses on a comparative analysis between traditional two-vector current control and four-vector current control. While the two-vector current control method is straightforward, the four-vector current control method offers superior capabilities in suppressing harmonic currents and improving motor control performance. Considering the high redundancy of the motor, this paper analyzes the open-circuit faults in dual-winding PMSMs and proposes two fault-tolerant control strategies. The hysteresis current fault-tolerant control strategy maintains the rotating magnetic motive force before and after the fault unchanged, optimizing for either minimum stator copper loss or maximum torque output to derive reference values for the remaining phase currents. This is implemented through hysteresis comparison, and simulations validate that this control strategy is simple and effective. The fault-tolerant control strategy based on normal decoupling transformation keeps the decoupling matrix unchanged and adjusts the reference current in the harmonic subspace to achieve stable operation under motor faults. This control strategy ensures performance and dynamic stability under different open-circuit fault conditions.