MOTOR CONTROL DEVICE AND CONTROL METHOD THEREFOR

A rail vehicle (10) comprises: a permanent magnet synchronous motor (3); an inverter (1) for driving the permanent magnet synchronous motor (3); and a vehicle speed sensor (9) for detecting the vehicle speed VTcar. The initial rotational speed Éest0 is estimated based on the vehicle speed VTcar; the angular velocity (Éest) is estimated, taking the initial rotational speed (Éest0) as the initial value; the rotational phase angle (¸est) is estimated based on the angular velocity (Éest); and the inverter (1) is controlled based on the rotational phase angle (¸est).