Abstract: In all home appliances and in small scale industries, single phase induction motors are most commonly used. iRecently remarkable efforts have been made in adjustable speed – single phase induction motor drives (SPIMD’s). iDifferent types of PWM strategies have been used in speed control of SPIMD’s, most widely sinusoidal PWM & space vector PWM strategies. Various converter technologies are taking a place in SPIMD’s because of its low cost. The proposed system describes the several PWM strategies with an AC chopper to control the speed of single phase induction motor. Asymmetrical PWM technique has been used to operate the power electronics switches (Triac) of an AC chopper. The main objective of this work is to make the speed of the single phase induction motor varying as per the required load conditions by using Asymmetrical PWM technique, which reduces the harmonic contents in motor and increasing the motor efficiency. The simulation is carried out in MATLAB/SIMULINK with a Split Phase Induction Motor, where the motor is operated in normal PWM strategy and Hysteresis PWM strategy. The hardware is designed for the Asymmetrical PWM technique and results have been obtained.

Keywords— AC Chopper, Asymmetrical PWM, Single Phase Induction Motor, Speed Control, Zero crossing.