Optimum supply for an inverter-fed cage induction motor at different load conditions

摘要

The effects of power supply on the energy efficiency of a form-wound cage induction motor are studied when the motor operates under light loads. The cage induction motor is modelled with the space and time discretized finite-element analysis. The resistive losses are taken into account accurately by modelling eddy currents in the form-wound multi-conductor stator winding and the rotor cage. The core losses are considered with conventional empirical equations. A pulse-width-modulated (PWM) voltage is used to supply the motor. The fundamental harmonic (FH) terminal voltage is decreased from its rated value and the slip is adjusted to achieve a particular load condition. The variation of the total electromagnetic as well as the stator resistive losses are analyzed to find the optimum supply.