PMSM Six-Step Operation and Dynamic Performance Analysis

Six-step operation of permanent magnetic synchronous machine (PMSM) machine is becoming highly demanded for several applications that rely on battery as energy source. The main advantages of the six-step operation are 1) expanding the average output torque in flux weakening region; 2) reducing inverter switching losses. Nevertheless, the d-q synchronous reference frame based current regulator is no longer applicable in six-step mode, since only voltage angle can be adjusted in six-step mode. In this paper, a new algorithm based on voltage-angle control is proposed to achieve six-step operation. This innovative algorithm renders the drive dynamic performance predictable and the controller can be readily tuned using linear control theory.