Abstract: The study of power electronic converters is vital to gain knowledge on Variable Speed Drives or Energy Efficient Drives. Induction motors are the load which contributes to about 70% of total loads used in the world. Variable speed drives are employed for industrial processes and in many applications. In this paper ac ac voltage controller is used to vary the input voltage to control the speed of the induction motor. The effect of harmonics and Total Harmonic Distortion (THD) is also studied in this paper.

Keywords: AC AC voltage controller, Phase Angle Control, Capacitor start induction motor, Total Harmonic Distortion.