Iron Loss and Magnetic Hysteresis Properties of Nanocrystalline Ring Core at High and Room Temperatures Under Inverter Excitation

This paper discusses the iron loss and magnetic hysteresis properties of a ring core of nanocrystalline magnetic materials (NMM) at room temperature (RT) and high temperature (HT) under pulse-width-modulation (PWM) inverter excitation. As in the case of the DC hysteresis loop, the coercivity of the NMM ring core at 300 ◦ C (HT) under PWM inverter excitation is larger than that at RT, mainly because of weakening of intergranular magnetic coupling at HT. In addition, in the NMM ring core, the area of the minor loops at HT increases compared with that at RT. Iron loss in the NMM core fed by the PWM inverter increases in tandem with an increase in temperature. Hysteresis loss increases dramatically in tandem with an increase in temperature for every tested case. In a low carrier frequency region, the eddy current loss at 300 ◦ C increases.