Healthy and Open-Phase Fault-Tolerant Unified Control for Dual Three-Phase PMSMs With Rapid Fault Response and False Alarm Recovery Capability

This paper proposes a healthy and open-phase fault tolerant unified control approach for dual three-phase permanent magnet synchronous machines (DT-PMSMs). The proposed approach enables seamless switch between healthy control and fault tolerant control (FTC). When open-phase fault happens, the proposed approach can rapidly respond to the fault within 1/20 electrical cycle. Moreover, when false alarm happens due to noise or disturbance, the proposed approach can switch back to the healthy control effectively. Firstly, a healthy and FT unified control model is derived through the analysis of currents under healthy and fault conditions. The model parameters are optimized to achieve full range minimum copper loss (FRML), and the analytical solutions are derived to improve the computation efficiency and ensure the optimal performance in the full range operating conditions. Compared with existing methods, the proposed approach can achieve higher efficiency and larger torque range. The proposed approach is verified on the test machine under different operating conditions and compared with existing methods in terms of the response speed to fault, copper loss, peak phase current and maximum attainable torque to show the performance improvement.