自动导引车无线充电系统中发射线圈优化设计

为解决无线充电系统中线圈间耦合系数小、充电效率低的问题,提出一种在不同传输距离下发射线圈和接收线圈半径匹配的优化设计方法。首先建立了该无线充电系统的等效电路,推导出传输效率与互感和线圈内阻的关系;其次对平面环形线圈进行等效建模,得到了两共轴平行圆线圈间的互感公式;然后在特定接收线圈下,利用线圈间互感公式和有限元仿真得到了平均半径比与传输距离的关系,并在自动导引车的充电距离下,优化设计了发射线圈的内外半径;最后对优化前后发射线圈进行了对比实验。实验结果表明,优化后发射线圈可以明显提升系统的传输效率,从而验证了所提设计方法的正确性。

Optimization Design of Transmitting Coil for Wireless Charging System in Automated Guided Vehicle

To solve the problems of small coupling coefficient between coils and low charging efficiency in a wireless charging system, an optimization design method of matching the radiuses of transmitting and receiving coils at different transmission distances was proposed. Firstly, an equivalent circuit of the wireless charging system was established, and the relationship among the transmission efficiency, mutual inductance, and internal resistance of the coil was derived. Secondly, the planar loop coil was equivalently modeled, and the formula for the mutual inductance between two parallel coaxial coils was obtained. Then, under a specific receiving coil, the relationship between the average radius ratio and transmission distance was obtained by using the mutual inductance formula and finite element simulation. In addition, the inside and outside radiuses of the transmitting coil were optimally designed at the charging distance of an automated guided vehicle. Finally, a comparison experiment on the transmitting coil before and after its optimization was carried out, and experimental results show that the optimized transmitting coil can obviously improve the transmission efficiency of the system, thus verifying the proposed design method.