Fault-Tolerant Model Predictive Control for Interturn Short Circuit Faults in Symmetrical Six-Phase PMSMs

Interturn short circuit faults (ISCF) of stator windings is one of the most dangerous faults in machine system. This paper proposes a novel fault-tolerant (FT) model predictive control (MPC) method for ISCF to suppress the torque ripple in symmetrical six-phase permanent magnet synchronous machines (PMSMs) by subspace current residuals without the use of extra voltage sensors or neutrals. For six-phase control systems, six-phase currents are usually mapped onto independent subspaces. The current behavior in each subspace is influenced by ISCF. To avoid the use of extra voltage sensors, the proposed cost function is generated by the subspace currents and residuals. Simulation results show the effectiveness of proposed method under different operating conditions and fault severities.