Analysis and Design of a Dual-Receiver WPT System With Constant Current and Constant Voltage Dual-Type Outputs

In some practical applications, such as mobile terminals and automated guided vehicles (AGVs), wireless power transfer (WPT) systems are required to have load-independent different types of output characteristics. However, the existing dual-receiver WPT systems have problems, such as unnecessary cross coupling, low space utilization, inability to achieve complete electrical isolation of the output ports, and complex design solutions. In order to solve the above problems, this article proposes a dual-receiver WPT system with constant current (CC) and constant voltage (CV) dual-type outputs. In this system, two solenoid coils connected in series and wound vertically serve as the transmitter coil, while two independent and mutually perpendicular solenoid coils serve as the two receiver coils. The mutually perpendicular solenoid coils are naturally decoupled. Consequently, the magnetic coupler is devoid of cross-coupling interference, simplifying the system design. First, a comprehensive theoretical analysis of the natural decoupling characteristics of the magnetic coupler is performed. Second, a detailed mathematical derivation of the dual-receiver WPT system with load-independent CC and CV dual-type output characteristics and zero phase angle (ZPA) operation is carried out. Third, the realization of the zero-voltage switching (ZVS) of the inverter and the influence of the change of the compensation components on the CC and CV dual-type outputs are analyzed in detail. Finally, an experimental prototype with 72-V CV output from the first-stage receiver and 3-A CC output from the second-stage receiver is built. The experimental results verify the correctness of the theoretical analysis.