Performance Enhancement of an Induction Motor by Secondary Impedance Control

This paper demonstrates the use of nonresistive secondary control of an induction motor to improve efficiency, power factor, and torque. A mathematical algorithm is presented to predict the control requirements in terms of secondary capacitance. The required secondary capacitance is implemented by a novel electronic switching technique that effectively increases the value of the used capacitor. This overcomes the high-capacitance demand and provides a feasible solution. Experimental verification is presented in the results obtained from a small induction motor drive.