Energetic Behavior of Soft Magnetic Materials in the Case of Inverter Supply

The energetic behavior of several samples of soft magnetic materials excited by inverter have been analyzed. The authors dealt with the iron loss increase due to the nonconventional voltage supply such as inverter-fed induction motors. Square-wave and PWM inverter voltages have been selected as the excitation waveforms for the samples under test, Extensive experimental results on good-quality nonoriented silicon steel, medium and high-quality grain-oriented silicon steel, and amorphous alloy would cores are presented. Furthermore., a detailed description of the testing procedure is reported. The results allow one to estimate the percentage of the iron loss increase with the nonsinusoidal supply. The comparison with the results obtained with the sinusoidal supply gives useful indications to the electromagnetic device designers about the “derating factor” to be used for devices fed by static power sources.