Research on Maximum Power Load of Wireless Power Transfer via Magnetic Resonance Coupling

In addressing the optimal load problem of magnetically resonant wireless power transfer (WPT) systems, this paper explores the relationship between the load that enables maximum transmission power, referred to as the maximum power load, and key system parameters. Using lumped parameter theory, the expression for the maximum power load is derived, followed by an analysis of how transmission distance, coupling coefficient, and operating frequency influence it. Circuit simulations were performed, and a two-coil WPT experimental platform was constructed to validate the theoretical findings. Both simulation and experimental results demonstrate that the maximum power load increases with the coupling coefficient but decreases as the transmission distance grows. Moreover, when the operating frequency deviates from the resonant frequency, the maximum power load is reduced.