Investigation of induction motor performance fed from PWM inverter

Electrical motors are designed on the basis of balanced three-phase sinusoidal input voltage. Non-sinusoidal voltage, which is the common output voltage from PWM inverters, has detrimental effects on induction motors performance characteristics, and derating of machine is required. In this paper the performance of a three-phase induction motor is intensively investigated when it is fed from PWM inverter. The PWM inverter is controlled by two different PWM techniques commonly used, namely Sinusoidal PWM Technique and Selected Harmonic Elimination PWM (SHEPWM) Technique. A complete simulation of a three-phase induction motor fed from PWM inverter was designed using Matlab/Simulink package. The performance of the three-phase induction motor loaded by fan load was compared with the performance of the motor where fed from pure sinusoidal supply voltage. The study confirms that the induction motor under study gives best performance when it is fed from PWM inverter controlled by SHEPWM technique.