针对水平偏移与电池充电时输出功率可控性较弱的问题,提出一种可重构无线充电系统WCS(wireless charging system).通过合理地切换传能通道,实现互感与负载较宽范围变化时恒流/恒压充电和全桥逆变器软开关ZVS(zero voltage switching)状态.首先,分析系统电路拓扑,推导系统参数与充电电流/电压、ZVS状态之间关系式,据此阐释系统重构与功率可控的合理性;其次,构造交叠线圈式磁耦合机构MCSC(magnetic coupler with sandwich coils),分析其水平偏移性能,为系统高偏移容忍度的设计提供依据;第三,分析WCS的工作流程,设计的闭环控制器实现了较宽偏移与负载波动时恒流/恒压充电、ZVS状态;最后,搭建旋翼无人机用WCS,实验结果表明,最大输出功率为 126 W且系统效率大于 85%时,水平偏移范围为直径 340 mm的圆形区域.
Aimed at the problems of horizontal misalignment and poor controllability of output power during battery charging,a reconfigurable wireless charging system(WCS)is proposed in this paper.The constant current/constant volt-age charging and zero voltage switching(ZVS)state for a full-bridge inverter are realized through reasonably switching power transmission channels when the mutual inductance and equivalent load resistance vary widely.First,the circuit topology of the system is analyzed,and an expression for the relationship among system parameters,charging current/voltage and ZVS state is derived,thus explaining the rationality of system reconfiguration and power controllability.Sec-ond,a magnetic coupler with sandwich coils(MCSC)is built,and its horizontal misalignment performance is analyzed,which provides a theoretical basis for the design of high misalignment tolerance of the system.Third,the workflow of WCS is analyzed,and a closed-loop controller is designed to realize constant current/constant voltage charging and ZVS state under a wide range of misalignment and load fluctuation.Finally,a WCS for UAV was built,and experimental results show that when the maximum output power was 126 W and the system efficiency was higher than 85%,the horizontal misalignment range was shifted to a circle with a diameter of 340 mm.