Studies have substantiated that the vibration and noise produced by iron core of an electromagnetic device are closely related to magnetostriction silicon steel sheet. Moreover, when induction motor works under condition frequency conversion, symmetry sheet will change, distribution field be asymmetric, which aggravate noise. This paper completes experimental measurement analysis characteristic...

In this paper, we develop a variable-frequency pulse width modulation (VFPWM) circuit for input control of 6.78-MHz resonant wireless power transfer (WPT) systems. The zero-voltage switching relies on the adjustments both duty cycle and frequency class-E amplifier used in WPT as transmission unit. High-frequency wave integrated circuits exist, but some have insufficiently high or unfavorable re...