The energic behaviour of two samples of soft magnetic materials fed by inverters have been studied. The authors dealt with the increase of the iron losses due to non conventional voltage supply. Six-step and PWM inverter output voltages have been selected as the excitation waveforms for the samples under test. Extensive experimental results on high quality grain oriented silicon steel and amorphous alloy wound core samples are presented. Furthermore, a detailed description of the testing procedure is shown. The results are quite informative and quantify the iron-loss increase with non sinusoidal supply in comparison with the results obtained by the standard tests (sinusoidal supply and Epstein method). The comparison can give useful indications to electromagnetic-device designers about the 'derating factors' for the different magnetic materials that have to be used in designing devices fed by static power sources.
