基于复合拓扑的无线电能传输系统优化策略

Efficiency Optimization Strategy of Wireless Power Transmission System Based on Composite Topology

在无线电能传输过程中,受初级发射线圈及次级接收线圈之间相对位置以及电池内阻在充电过程中随时间变化的影响,线圈之间耦合情况以及系统负载大小在电能传输过程中动态变化,导致系统偏离最优效率工作点而引起传输效率下降。针对该问题,提出基于LCL-S型拓扑的无线电能传输系统效率优化策略。首先根据电路原理对系统进行理论分析,其次,根据谐振拓扑次级输出电压和初级输入电压有效值之比与负载解耦的特点,提出线圈互感大小估算方法,并通过对负载侧Buck-Boost电路控制信号施加扰动,寻找最优效率工作点,实现系统在电池恒流-恒压充电模式下效率优化。最后基于半实物仿真平台实验验证了该方法的有效性和可行性。

In the process of wireless power transmission,due to the influence of the relative position between the primary side transmitting coil and the secondary side receiving coil and the change of the battery internal resistance with time in the charging process,the coupling between the coils and the dynamic change of the system load in the power transmission process lead to the deviation of the system from the optimal efficiency working point and the decrease of the transmission efficiency.To solve this problem,the efficiency optimization strategy of wireless power transmission system based on LCL-S topology is proposed.Firstly,according to the circuit principle,the system is analyzed theoretically.Secondly,according to the characteristics of the ratio of the effective value of the secondary side output voltage and the primary side input voltage of the resonant topology and the load decoupling,the estimation method of coil mutual inductance is proposed.By applying disturbance to the control signal of the load side Buck-Boost circuit,the optimal efficiency working point is found to realize the efficiency optimization of the system under the constant current-constant voltage charging mode of the battery.Finally,the effectiveness and feasibility of the proposed method are verified by the hardware in the loop simulation platform.