Short Circuit Behavior of Dual Three-phase Permanent Magnet Synchronous Motors with Different Mutual Inductance in Electric Propulsion Application

The dual three-phase permanent magnet synchronous motors (DTP-PMSMs) are suitable in aircraft electric propulsion unit (EPU) application because of their good reliability and fault-tolerant capability. However, this fault-tolerant capability can get weakened or even eliminated in short circuit fault due to the influence of flux coupling between the two isolated three-phase sub-systems. In this paper, a mathematical model of DTP-PMSMs with different mutual inductance between the two sub-systems is developed and analyzed. Based on the model, different short circuit protection methods are discussed and compared. Finally, a simulation of an EPU consisting of a DTP-PMSM, and a simplified constant speed propeller (CSP), is implemented to verify the short circuit behaviors.