大传输距离下电动汽车无线充电系统优化

Optimization of Wireless Charging System for Electric Vehicles With Large Transmission Distance

针对无线充电系统原边线圈嵌入路面结构后耦合线圈之间的距离增大、耦合程度减弱的问题,对线圈结构进行优化,以实现大传输距离下无线电能的传输。通过电磁有限元仿真对线圈的内径、外径和匝数进行优化,提出以耦合系数为优化目标的线圈结构参数优化流程,同时,在Simulink中搭建无线充电系统的电路仿真平台,对采用优化后线圈结构的无线充电系统性能进行测试。结果表明:随着线圈内径增大,耦合系数先增大,达到峰值后迅速减小;随着线圈外径增大,耦合系数逐渐增大;在不同外径下,线圈的最优匝数均为9匝;3个参数中,增大外径是提高线圈耦合程度最有效的方式;最终优化后线圈的参数为外径480 mm、内径210 mm、匝数9匝,可以实现300 mm距离的电能传输,系统输出功率保持在2.96~3.70 kW,传输效率达到86.54%,横向容许偏移距离可达60 mm。

In response to the problem that the distance between the coupling coils increases and the coupling degree decreases after the primary coil in wireless charging system is embedded into the pavement structure,the coil structure was optimized to realize the wireless transmission of energy over large distances.The inner diameter,outer diameter and number of turns of the coil were optimized by electromagnetic finite element simulation,and the optimization process of the coil structure parameters with the coupling coefficient as the optimization target was proposed.Meanwhile,the circuit simulation platform of the wireless charging system was built in Simulink,and the performance of the wireless charging system with the optimized coil structure was tested.Results show that with the increase of coil diameter,the coupling coefficient first increases to the peak and then decreases rapidly,and the coupling coefficient gradually increases as the outer diameter of the coil increases.The optimal number of turns of the coil is 9 turns for different outer diameters.Among the three coil parameters,increasing the outside diameter is the most effective way to increase the coil coupling degree.The final optimized parameters of the coil are the outer diameter of 480 mm,the inner diameter of 210 mm,and the number of turns of 9,which can achieve the power transmission at a distance of 300 mm.The output power of the system is maintained between 2.96 kW and 3.70 kW,and the transmission efficiency reaches 86.54%.Besides,the allowable lateral offset distance of the coil is up to 60 mm.