Extension of the Output Speed Range of an Open-End Winding IPMSM Using an Induced Voltage-Limiting Ellipse

Abstract

This study proposes a control method for a dual inverter to extend the output speed range of an interior permanent magnet synchronous motor with open-ended windings. The secondary inverter with a floating capacitor for the dual inverter supplies reactive power to the motor. In the proposed method, the reactive power required to drive the motor is calculated using an inductive voltage-limiting ellipse, and the d-axis current reference value and output voltage of the secondary inverter are determined. In the proposed control method, the primary inverter of the dual inverter supplies the effective power to the motor to expand the output speed range. The experimental results indicate that the output speed range is significantly improved and the constant torque region is expanded by approximately 41% compared with that in the conventional method.