Iron Loss Evaluation of GaN PWM-Supplied Magnetic Cores for MHz Converters in More Electric Aircrafts-400Hz case

Abstract

Nowadays, there is a great interest in industry for outstanding magnetic materials with low iron loss properties especially for aerospace applications where high efficiency and ultra-low weight are mandatory. In fact, aerospace applications, especially more electric aircrafts, have adopted 400Hz as fundamental frequency for their electric sub-systems. However, with the introduction of wide bandgap semiconductors, magnetic materials have been required to operate at higher switching frequencies (MHz order), bringing new challenges as magnetic materials has been proven, designed, and operated for low frequency operation (Hz and kHz order). Therefore, magnetic characterization at those high frequency levels, that current technology demands, is required. This paper introduces the characterization and comparison procedures between iron losses under conventional 50Hz and novel 400Hz operation when the system is driven at high switching frequency. In this comparison, conventional electrical steel is utilized with special attention to the loss breakdown between eddy-current, hysteresis, and excess losses.