Multireference-Frame based Model Predictive Fault-Tolerant Control for Dual Three-Phase Permanent Magnet Synchronous Machines

This paper proposes a model predictive fault-tolerant control (MP-FTC) strategy for dual three-phase permanent magnet synchronous machines (DT-PMSMs) to enhance dynamic performance and enable wide-speed-range operation under open-phase fault (OPF) conditions. To achieve this, a current prediction framework is established based on a post-fault machine model derived from the negative-sequence cancellation principle. The resulting predictive current controller directly tracks AC reference currents, thereby avoiding low-pass filters and multiple proportional-integral (PI) controllers. Then the voltage and current constraints under OPF are analyzed, and reconstructed voltage-current-speed trajectories above and below the base speed are derived using phase current amplitudes as variables. On this basis, a wide-speed-range operating trajectory optimization algorithm (WSR-OTOA) is formulated to generate unified maximum torque per ampere (MTPA)-field weakening (FW) current references based on the reconstructed voltage-current-speed trajectories.