Short-Circuit Fault-Tolerant Control Without Constraint on the D-Axis Armature Magnetomotive Force for Five-Phase PMSM

In this article, we investigate the short-circuit (SC) fault-tolerant control (FTC) method for a five-phase permanent-magnet synchronous machine (PMSM) with surface-mounted permanent magnets. By relieving the constraint of zero d -axis armature magnetomotive force (MMF) and restraining the backward-rotating MMF components to be zero, round-rotating armature MMF with maximum q -axis armature MMF is achieved, which enables five-phase PMSM to output maximum smooth torque with lower losses and higher efficiency under SC fault condition. To ensure smooth postfault operation in full-speed range, the influence of winding resistance on SC current is further considered, which improves low-speed operation performance. The proposed FTC method features sinusoidal currents with equal amplitude, which ensures better control simplicity and postfault thermal uniformity between phases. The finite-element analysis and experiments are carried out to verify the proposed method.