Efficiency issues in induction motor drives: Modelling and losses minimization techniques

This paper presents an efficiency analysis on an inverter-fed induction motor drive integrating both switching losses minimization by D-PWM for the inverter and an ELMT for the motor. The target is the evaluation of the contribution of both the chosen PWM and ELMT strategies on the total losses of the drive. To this aim, a complete dynamic model of the drive system has been developed and implemented in Matlab-Simulink environment permitting efficiency to be evaluated in numerical simulation, properly suitably separating each loss term. Experimental results show that the integrated use of D-PWM and ELMT permits a reduction of the overall power loss up to 6% of the induction machine rated power at low load torques. Correspondingly, the drive efficiency can be increased up to about 30% at low loads and up to about 5% at high loads.