Sensorless performance optimization of single-phase induction motors

Single-phase induction motors suffer from low torque average and high torque pulsations. These problems can be overcome by a switching capacitor in series with the stator auxiliary winding. However, the switching of the capacitor requires the motor speed signal over the entire speed range to provide performance optimization in terms of high torque average and low torque pulsations. In this paper a simple speed estimation method for single-phase induction motors is proposed in the stationary reference frame to overcome the problems associated with the use of speed sensors. Based on this method, a sensorless torque optimization system is suggested. The system is then validated by extensive simulation results. The speed estimation method was used in the sensorless control of the motors.