A single-stage wireless power transfer (WPT) system based on the switching control capacitor (SCC) is proposed in this paper. Using the SCC instead of an ordinary capacitor gives the WPT system, an additional control degree of freedom. The proposed robust WPT system has a constant power (CP) output characteristic under a wide range of load resistance and coupling coefficient variations by adjusting the conduction angle of the SCC. When compared with constant current (CC) charging, CP charging can shorten the charging time and promote battery cycle life. Moreover, a primary side control method is proposed. It only needs to sample the primary current to identify the reflected impedance, which avoids wireless communication. When combined with the control strategy, the condition of zero-voltage switching (ZVS) is derived. Finally, a 125-W experimental prototype is built to verify the performance of the proposed method. Experimental results demonstrate that stable CP charging can be maintained during coil movement and load changes. In addition, soft switching is implemented in all situations.

本文提出了一种基于开关控制电容器（SCC）的单级无线电力传输（WPT）系统。使用 SCC 代替普通电容器为 WPT 系统提供了额外的控制自由度。通过调整 SCC 的导通角，所提出的鲁棒 WPT 系统在宽负载电阻和耦合系数变化范围内具有恒定功率 (CP) 输出特性。与恒流（CC）充电相比，CP充电可以缩短充电时间，提高电池循环寿命。此外，提出了一种初级侧控制方法。它只需要对初级电流进行采样即可识别反射阻抗，从而避免了无线通信。结合控制策略，导出了零电压切换（ZVS）的条件。最后，建立了一个 125-W 的实验原型来验证所提出方法的性能。实验结果表明，在线圈运动和负载变化期间，可以保持稳定的 CP 充电。此外，在所有情况下都实现了软切换。