Optimal excitation of a permanent magnet synchronous motor having an open-circuit phase

Optimal excitation of a three-phase permanent magnet synchronous motor with an open-circuit winding fault is considered. A model of motor torque development with a failed winding is first presented using Fourier analysis. Then, a design procedure based on knowledge of the motor magnetic characteristic is developed. The average torque is maximized using the design approach, and torque ripple is reduced as the order of the optimal solution is increased. Two design examples are presented.