PMSM Current Management with Overcurrent Regulation

Abstract

In many vehicle systems, the permanent magnet synchronous machines (PMSMs) are critical components which provide system propulsion. This work proposes a PMSM current management method with overcurrent regulation. The proposed current management method aims at achieving online machine current trajectory tracking and overcurrent regulation. The current trajectory tracking is to explore optimal current commands which ensure maximum system efficiency or maximum torque under machine voltage capability, and the overcurrent regulation is to limit machine current and thereby enhance the system reliability by reducing overcurrent risk of machine and inverter. The proposed method is easy to implement, capable of achieving online overcurrent regulation while maintaining maximum torque per ampere (MTPA) and maximum torque per voltage (MTPV) control without requiring offline calibration, and flexible to tune under changing machine current constraint and system parameter variations.