Investigating PWM-Induced Iron Losses. Measurements and Estimation Models up to 350 kHz Switching Frequency

This article deals with the investigation of iron losses in toroidally wound laminated magnetic cores excited with wide-bandgap-device-based power electronic converters. The study aims to analyze the impact of selected pulsewidth modulation voltages on the iron losses, through an extensive experimental measurement campaign. In particular, four toroidal specimens made of different magnetic materials are supplied by pulsewidth-modulated voltage waveforms with switching frequencies ranging from 1 to 350 kHz and different deadtimes. Test campaigns have been conducted with the dual objectives of critically reviewing an engineering method proposed in the prior literature for predicting iron losses under distorted voltage waveforms. Additionally, the aim is to extend this estimation model to accommodate the highest frequen- cies currently employed in high-speed ac motor drives equipped with wide-bandgap semiconductor power converters.