A Constant Current and Constant Voltage Dual-Output Wireless Power Transfer System Based on Receiving Side Decoupling: Analysis, Design, and Verification

In order to solve the problem that the automatic guided vehicle requires load-independent constant current (CC) and constant voltage (CV) dual-type outputs, it is necessary to design a dual-output wireless power transfer (WPT) system with different output types. However, the existing dual-output WPT systems have problems such as unnecessary cross-coupling, limited space utilization, and complex control methods; therefore, this paper proposes a CC and CV dual-output WPT system based on receiving side decoupling. In the system, the transmitting side coil uses a Q-type coil and a solenoid coil that are connected in series and wound vertically, and the receiving side coil uses a Q-type coil and a solenoid coil that are independent and perpendicular to each other; the mutually perpendicular Q-coil and solenoid coils are naturally decoupled, thus eliminating the effects of cross coupling in the system. First, the decoupling characteristics of the proposed magnetic coupler are analyzed in detail. Second, a mathematical model is established based on the decoupling of the magnetic coupler, and the load-independent output characteristics of the dual-output WPT system and the input impedance showing pure resistance characteristics are derived in detail. Then, the output characteristics under ZPA conditions that can be achieved by the system are further verified through simulation analysis. In addition, in order to reduce the conduction loss of the switch tube in the system, the influence of the change of compensation component parameters on the realization of zero voltage switching is analyzed through normalized simulation. Finally, an experimental prototype is built, achieving CC output of 3.5 A and CV output of 70 V, verifying the correctness of the above theoretical analysis. In addition, when the first receiving side load $R_{B1}$ is 30 $\Omega$ and the second receiving side load $R_{B2}$ is 19 $\Omega$, the peak efficiency can reach 92.6%.