Optimal performance of capacitor-run single phase induction motor

In this article are presented experimental results of a capacitor-run single phase induction motor. Representative curves for the motor were plotted directly from acquired data and by off-line computer calculus program. The method used for improving motor's efficiency is by varying according to the torque the value of the capacitor inserted in the auxiliary winding. To determine the maximum efficiency for a given torque measurements were made with large number of fixed value capacitors. Regarding motor's special construction experiments were repeated for each of the two independent windings. Tests were performed for different capacitor and torque values to determine the output power. Also the starting torque was determined. A low noise data acquisition system was used in order to obtain the motor's input currents and voltages. An off-line analysis of the acquired data was necessary to determine the optimal capacitor for a maximum efficiency. Theoretical calculus for optimal capacitor value is presented.