Optimal Design of a Wireless Power System with the Filter Theory

Magnetic coupled wireless power transfer (WPT) systems often face challenges in output efficiency degradation due to changes in relative position or load variations. Existing design methods often result in an increase in circuit complexity and an inability to address both distance changes and misalignments simultaneously. In this paper, we present a novel WPT system design method grounded in filter theory. This method treats mutual inductance as a variable corresponding to the frequency parameter in filter design. We then employ the well-established filter design theory to develop multi-coil WPT systems. Using both first-order and second-order Chebyshev filters as the sample, through simulations and experiments, we validate our proposed method and achieve stable transmission efficiency within a specific interval of mutual inductance and load variation.