无线充电系统三种耦合线圈偏移特性研究

Research on Offset Characteristics of Three Coupling Coils in Wireless Charging System

不同无线电动汽车厂家制造的发射线圈与接收线圈的偏移特性是保证国内外汽车充电、互联互通的关键性问题。对3.7 kW无线电能传输系统进行建模,针对无线充电的SS型拓扑结构进行推导,得出输出功率和传能效率表达式,又对方形-圆形线圈间互感进行偏移性研究,理论推出线圈平行时进行横向偏移对互感系数的表达式,进而得出偏移距离对传输特性的影响。建立有限元仿真模型,对比圆-方形、DD-方形、DD-圆形三种线圈在一定偏移距离内传输特性的变化,搭建实验平台验证,结果表明,圆-方形线圈间抗偏移特性最强,在一定范围内偏移对耦合系数、传能效率、输出功率三方面均与方-方形线圈传输特性接近。DD-圆形与DD-方形线圈组合在DD线圈非中轴线方向偏移时传输特性比正对时要好,传输特性均有提高,中轴方向很差。该研究为不同线圈间高效充电提供了参考。

The offset characteristics of transmitting and receiving coils manufactured by different wireless electric vehicle manufacturers are a critical issue to ensure the interconnection of domestic and international vehicle charging. The 3.7 kW wireless energy transmission system was modeled and the SS-type topology of wireless charging was derived to obtained the expressions for output power and energy transfer efficiency. The study of the offset charateristics was also conducted for the mutual inductance between square-circular coils,and the expressions for the mutual inductance coefficient were theoretically introduced for the lateral offset performed when the coils were parallel,and then the effect of offset distance on the transmission characteristics was derived. The finite element simulation model was established to compare the changes of transmission characteristics of circle-square,DD-square and DD-circle coils within a certain offset distance,and an experimental platform was built to verify the results,which show that the anti-offset characteristics between circle-square coils are the strongest,and the offset effects on coupling coefficient,energy transfer efficiency and output power within a certain range are close to those of square-square coils. DD-circle and DD-square coil combinations have better transmission characteristics when the DD coils are offset in the non-central direction than when they are square,and the transmission characteristics are both improved,and very poor in the central direction. This study provides a reference for efficient charging between different coils.