Periodic Energy Control for Wireless Power Transfer System

Wireless power transfer (WPT) systems are widely applied in many scenes due to their safety, convenience, and flexibility. This letter proposes a novel control strategy named Periodic Energy Control (PEC) in WPT systems. It is suitable for all kinds of compensation topologies of WPT systems. Specifically, it takes the energy input to the resonant network as the control target, which calculates the energy input by measuring the capacitor voltage or the inductor current, thereby controlling the switching action of the inverter. Meanwhile, it not only effectively suppresses the overvoltage (or overcurrent) when system parameters such as load and mutual inductance change, but also features low sensitivity to mutual inductance, which has advantages in the scene where mutual inductance changes. Moreover, this letter presents the principle of PEC and derives the energy input to the resonant network in various compensation topologies of WPT systems. Finally, experiments are presented to verify the effectiveness of this control method.