Energetic behavior of soft magnetic materials fed by inverter supply

The energetic behavior of several samples of soft magnetic materials excited by inverter voltage supplies has been analyzed. The iron losses increasing due to nonconventional voltage supply such as inverter-fed induction motors have been considered. Square wave and pulse-width-modulated (PWM) inverter voltages have been selected as the excitation waveforms for the samples under test. Extensive experimental results on medium- and high-quality grain oriented silicon steel and amorphous alloy wound cores are presented. A detailed description of the testing procedure is also reported. The results allow one to estimate the percentage of the iron losses increasing the nonsinusoidal supply. Comparison with the results obtained with sinusoidal supply gives useful indications to electromagnetic device designers about the derating factor to be used in devices fed by static power sources