Adjustable capacitor for the single-phase IM performance improvement

A single-phase induction motor equipped with the additional auxiliary winding in series with an adjustable capacitor is analyzed on the basis of rotating field theory. Effects of capacitor variation on the motor characteristics including efficiency, electromagnetic torque, pulsating torque, power factor and current in the specified speed range are analyzed. As different capacitances are required in different situations, an adjustable capacitor is introduced that achieves this requirement. According to the performance factor that is selected to be improved, proper control strategy will be applied. Finally, simulation results of maximum efficiency strategy are demonstrated to verify the applicability of the analyses.