基于LCL-LCL/S混合自切换谐振式无线充电系统

Hybrid Self-Switching Resonant Wireless Charging System Based on LCL-LCL/S

为了减少混合谐振式无线充电系统的开关器件和无源元件数量,提高系统输出功率,同时简化原、副边的控制策略,提出一种基于LCL-LCL/S混合自切换谐振式无线充电系统,无需原、副边通信和增加任何无源元件,仅通过LCL结构的自投切操作更改拓扑网络来实现无线充电系统恒流恒压的切换。首先,依靠T型网络分析恒流或恒压输出与输入阻抗呈纯阻性的关系;然后,引入混合型补偿网络数学模型,分析实现系统输入电流和电压之间零相角(ZPA)与恒流或恒压输出特性的参数配置条件;接着,依据蓄电池充电曲线特征、谐振电流阈值、电压跳变阈值和耦合系数变化约束,进一步提出一种适用于混合谐振式拓扑网络参数优化的设计方法,在避免谐振网络参数经验选值的局限性导致参数不确定性问题的同时,也为参数选取提供了理论依据;最后,搭建实验平台验证该方案的可行性与有效性。实验结果表明,优化谐振网络参数的无线充电系统具有较好的恒流恒压输出特性,系统最大传输效率为81%,完全满足恒流恒压无线充电需求。

This paper aims to reduce the number of switching devices and passive components in a hybrid topology charging system,improve the output power of the system,and simplify the control strategy of the primary and secondary sides.A hybrid self-switching resonant wireless charging system based on LCL-LCL/S is proposed,which does not need primary and secondary side communication or any passive components.The constant current and constant voltage switching of the wireless charging system is realized only by changing the network topology through the automatic switching operation of the LCL structure.Firstly,a relationship between constant current or constant voltage output and input impedance was analyzed by a T-type network.Then,a mathematical model of the hybrid compensation network was introduced to analyze the parameter configuration conditions for realizing the zero-phase angle(ZPA)between the input current and voltage of the system and the constant current or constant voltage output characteristics.Next,according to the characteristics of the battery charging curve,resonant current threshold,voltage jump threshold,and coupling coefficient change constraints,a design method suitable for hybrid resonant topology network parameter optimization was proposed.This solution not only avoids the problem of parameter uncertainty caused by the limitation of empirical selection of resonant network parameters,but also provides a theoretical basis for parameter selection.Finally,an experimental platform was built to verify the feasibility and effectiveness of the solution.The experimental results show that the wireless charging system with optimized resonant network parameters possesses good constant current and constant voltage output characteristics.The maximum transmission efficiency of the system is 81%,which fully meets the requirements of constant current and constant voltage wireless charging.