Design, Analysis, and Verification of a Decoupled Dual-Output Wireless Power Transfer System with a Constant Voltage Output and a Constant Current Output

Wireless power transfer (WPT) is extensively utilized because of its isolation and convenience. However, WPT systems require different types of outputs in specific applications. The existing dual-receiving WPT system has disadvantages such as redundant compensation components, unnecessary cross-coupling interference, complex control circuits, and low space utilization. To address these shortcomings, this paper proposes a dual-output WPT system capable of delivering both constant voltage (CV) and constant current (CC) outputs simultaneously. The WPT system utilizes a special coil structure design, in which the DD coil is used as the transmitter coil and the first receiver coil, and the Q coil is used as the relay coil and the second receiver coil. In addition, the DD coil and the Q coil can achieve natural decoupling under alignment conditions. Consequently, the impact of the unnecessary cross-coupling within the system can be eradicated. Initially, the natural decoupling properties of the magnetic coupler are analyzed from a theoretical perspective. Subsequently, a mathematical model for the proposed WPT system is constructed. Through theoretical deductions, it is demonstrated that under the zero-phase-angle (ZPA) conditions, the system is capable of attaining a CC output at the first receiving side and a CV output at the second receiving side. Finally, a verification experimental prototype with a constant voltage output of 72 V and a constant current output of 2.5 A was built. The experimental results verified the accuracy of the previous theoretical analysis.