The characteristics analysis of PWM inverter-fed 3-phase induction motor from view point of saturation

This paper describes how to analyze the characteristics of a PWM inverter-fed three-phase induction motor in considering saturation by different means from those conventionally used. Starting and steady-state characteristics of such inverter drive are presented. In the steady-state, torque characteristics are presented under irregular on-off times of the PWM inverter drive. Flux loci, currents and torques are presented with the lapse of time. Above all, the flux locus is most interesting and it is important to know how the flux is formed and reaches saturation. Saturation helps a machine come to the steady-state far quicker and reduces vibration torque. This paper shows how the saturation exerts influence upon a motor´s starting and steady-state characteristics