Communication-Free Long-Distance Wireless Charging System for Battery Load With Adaptive Switching of Constant Voltage and Constant Current

Domino wireless power transfer (D-WPT) has excellent advantages in long-distance wireless power supply for equipment in complex spaces unsuitable for maintenance. A simple receiver (Rx) will reduce the failure rate and system maintenance costs. This article proposes a D-WPT system with battery state of charge (SOC) perception at the transmitter (Tx) and adaptive adjustment of constant voltage (CV) and constant current (CC) output. Specifically, we construct a two-port network circuit model for the
${n}$
-coil D-WPT system and propose the SOC identification method that uses the voltage and current of the Tx as input. Then, an adaptive output regulation strategy is constructed that uses a hybrid topology at the Tx to achieve the system’s CV or CC output. The system does not require Rx and Tx communication. Finally, an experimental platform with six coils and a 0.5 m transmission distance was established to verify the system’s effectiveness. The results show that the system can accurately identify the change in the battery load charging state and adaptively switch between CC and CV. The maximum system efficiency is 70%.