Sampling frequency influence on magnetic characteristic evaluation under high frequency GaN inverter excitation

Nowadays, there is a great interest on new magnetic materials and their outstanding properties of low iron losses. However, when a magnetic material is experimentally characterized, it is important to select a suitable sampling frequency specially when the inverter is driven at a high carrier frequency. Nevertheless, iron losses of a magnetic material under inverter excitation are usually underestimated when the inverter is driven at an insufficient sampling frequency. This paper introduces the iron losses of a magnetic material at high carrier frequency excitation using a GANFET inverter. In addition, the experimental evaluation of iron losses at several sampling frequencies is presented. As a result of the measurements, at low sampling frequencies, minor loops of BH curves could not be well constructed, because the inverter waveforms are not measured properly. Finally, experimental tests at 100 kHz and 1 MHz of carrier frequency presented an underestimation of 21.4% and 25.1%, respectively. This measurement error is presented when the inverter is driven at a sampling frequency lower than the suitable one.