Power factor correction of induction motors using PWM inverter fed auxiliary stator winding

A scheme for power factor correction of an induction machine by using an auxiliary stator winding in conjunction with a PWM voltage inverter and a capacitor on the DC side of the inverter is described in this paper. The operating principle of the proposed scheme is explained and a criterion is developed to select the optimum value of the power factor at which the scheme gives best performance. Simulation and experimental studies show that the harmonic components in the PWM output voltage can be reduced to obtain nearly sinusoidal current.