Unity power factor operation for 3-phase induction motors

This paper describes the possibility of unity power factor operation for three-phase induction motors. The basic idea is to use static reactive power compensation (SVC) with a double-stator winding three-phase induction motor to provide such operation. The compensator consists of a three-phase pulse width modulated (PWM) voltage source inverter connected to either a self or independently controlled DC bus. The voltage-source PWM inverter is connected to one set of the stator windings of the induction machine, while the other set is connected directly to the supply. The system has been studied theoretically and implemented using a shunt and a series type SVC. A microcontroller-based system has been tested in the laboratory to evaluate the motor performance.