Loss items evaluation in induction motors fed by Six-Step VSI

At present time, induction motors are widely supplied from several types of solid-state adjustable voltage-frequency controllers with a wide range of operating features. However, in any case, the motor has to be derated for the harmonic effects due to the non-sinusoidal nature of the supply voltage. The authors propose a simple method based on the no-load and short circuit test in order to get the useful machine parameters to adopt in equivalent circuit model for the losses evaluation. Complete experimental results are reported and the comparison between six-step and sinusoidal supplies are summarized.