Energy Efficient Drive for a Single-Phase Induction Motor Based on THD

Due to high reliability and easy availability of single phase supply, single phase induction motors (SPIM) are very popular for commercial as well as industrial applications. Here a capacitor start capacitor run SPIM is considered. The efficiency of the motor can be improve by reducing the harmonic content present at the input supply. Variable speed operation of SPIM can be achieved by driving the motor with an adjustable speed drive. Among the different existing driving topologies, three important topologies based on pulse width modulation (PWM) methods are identified and Simulink model for the entire system is developed. For measuring the effect of harmonics on the performance of the motor and for selecting a suitable energy efficient drive for SPIM, total harmonic distortion (THD) of the different topologies are plotted and compared. The value of THD is minimum for an energy efficient drive. From the analysis, single phase PWM inverter with half bridge rectifier drives is having minimum THD of 38.11% and is identified as an energy efficient drive for the induction motors.