Efficiency Determination of Inverter - Fed Induction Machines and the Impacts of the Inverter Supply

The proportion of inverter-fed induction machines for the solution of drive tasks has been steadily increasing. Therefore., the efficiency determination of induction machines fed by PWM inverter., as a measure of the energy efficiency of the system., is becoming more significant. This paper analyzes the efficiency determination for inverter operation according to the standard IEC 60034-2-3 and the possibility to apply the standard IEC 60034-2-1., defined only for sinusoidal supply., with inverter supply too. Furthermore., the additional harmonic motor losses caused by PWM inverter supply are determined and analyzed. This paper than provides information on the effects of the inverter supply on the separate losses and the efficiency in comparison to the sinusoidal supply.