Studies on a sensorless starting method for self-controlled synchronous motors without

A sensorless starting method for self-controlled synchronous motors without damper windings is proposed. The proposed method is based on the fact that electromotive forces induced in the armature windings due to the change in field current depend on the rotor position of the motor. The usefulness of a rotor position detecting method without any sensor is demonstrated by experimental investigations. And it is shown that the motor can be started up successfully by the proposed starting method on the basis of the estimated rotor position information.