Extension of the Operating Region of an IPM Motor Utilizing Series Compensation

This paper investigates the possibility of extending the operating region of a permanent-magnet (PM) motor constrained by a given power-supply voltage by using an open-winding motor drive configuration. A second inverter with a floating capacitor can be controlled to provide reactive power to the motor. A control method for the new open-winding PM machine drive employing flexible alternating current transmission systems concepts is proposed. Simulation and experimental studies on a laboratory scale interior PM machine are presented. The results show that the proposed method is able to considerably improve the power capability of the motor beyond its base speed.