A Parameter Robust Fault-Tolerant Control Scheme for Open-Winding Permanent Magnet Synchronous Motors in Flux-Weakening Regions

Under harsh operating conditions, open-phase fault and motor parameter mismatch may occur at the same time. Additionally, in high-speed operations, effective flux-weakening control is also important for fault-tolerant control. In order to solve the above problems simultaneously, this paper proposes a parameter robust fault-tolerant control scheme for open-winding permanent magnet synchronous motors (OW-PMSM) in flux-weakening regions. Firstly, the post-fault mathematical model of OW-PMSM is analyzed, and the fault-tolerant control method based on deadbeat predictive current control (DPCC) and alternate sub-hexagonal center pulse-width modulation (ASC-PWM) with zero voltage vector redistribution is introduced. Then, a sliding mode observer (SMO) is constructed for fault-tolerant control to estimate and eliminate the parameter mismatch disturbance. The stability of the SMO is analyzed by the Lyapunov function. Finally, a flux-weakening control method, based on voltage vector duration, is designed to combine with fault-tolerant control, which can improve the performance of the OW-PMSM at high speeds. To verify the availability and improvement of the proposed method, the conventional fault-tolerant control method and the proposed fault-tolerant control method were compared by sufficient experiments.