Iron loss characteristics of motors fed by fast switching GaN‐FET inverters

Abstract

Iron losses generated in a motor made of nonoriented electrical steel and driven by an inverter consisting of fast switching power semiconductor devices, GaN‐FETs were studied. The rectangular voltage pulses from the pulse width modulation applied to the motor generate not only a fundamental current but also harmonic currents. One of them increases considerably at the resonant frequency of the L, R, and C components in the motor. The phenomenon is called ringing. The ringing current, as well as the other currents, result in their respective iron losses. This study experimentally confirms that ringing occurs in the motor and quantitatively evaluates the iron loss related to it. The proportional dependence of the loss on the carrier frequency of PWM is found out.

Reduction of MHz Electromagnetic Ringing Losses in Magnetic Materials under GaN Inverter Excitation using Low-Pass Filter

“…5 describes the iron and copper losses with respect to switching frequency. Iron loss decreases with switching frequency below 100 kHz due to skin effect and increases above 100 kHz due to ringing loss (6) . The Fig.…”

Analysis of high‐frequency electromagnetic ringing phenomenon under GaN‐FET inverter excitation

“…These ringing phenomena cause noise; moreover, they contribute to iron loss when devices are operated at high carrier frequencies to reduce carrier iron loss. In motors, iron loss due to ringing may amount to 40% of total iron loss 5,7,8 . Thus, elucidation of ringing phenomena is an important issue.…”