Online Postfault Strategy of Minimum Copper Loss in Full Torque Operation Range for Dual Three-Phase PMSM Under Single Open-Phase Fault

Fault-tolerant ability of dual three-phase permanent magnet synchronous motors (PMSMs) is crucial for safetycritical applications. When a single open-phase fault occurs, the current references in conventional methods must be adjusted for avoiding the generation of torque ripple. Meanwhile, their design should balance the tradeoff between the torque operation range (TOR) and the copper loss. However, these post-fault current references still need to be re-tailored under different open-phase fault locations; otherwise, more severe system damage may occur. Aiming to improve the robustness of the control algorithm, this paper has proposed an online post-fault strategy that can achieve minimum copper loss while maximizing the TOR for dual threephase PMSMs with sinusoidal back-EMF. Unlike existing literature, the current reference in the harmonic subspace can be uniformly determined by the intermediate variable of phase shift and amplitude ratio, independent of fault scenarios. Additionally, the required fault identification is reduced from locating a specific phase to identifying one set of three-phase windings. The post-fault performance of minimum copper loss can be achieved during the full TOR. Furthermore, the implementation of proposed algorithm does not require any optimization iterative process or look-up tables. Comprehensive experimental results have verified the effectiveness of the proposed method.