在电动汽车无线充电系统中,负载锂电池的充电过程为先恒流再恒压,因此WPT系统需要同时具备实现两种输出状态的能力,且可以在两种输出状态之间进行平稳切换。基于此本文分析双边LCC拓扑实现负载无关的恒流和恒压输出的条件,并给出了参数设计方法。针对系统可能会随机在不同方向上出现位移的情况,采用了一种双向同轴平面线圈的结构,即原边线圈由内外两个沿相反方向绕制的线圈串联组成。通过仿真和实验验证了本文提出的电动汽车无线充电系统具备同时实现恒流\恒压输出的能力,且在多方向偏移工况下仍能实现稳定输出。

In the EV wireless charging system, the charging process of the loaded lithium battery is constant current followed by constant voltage. Therefore, the WPT system needs to have the ability to achieve two output states at the same time, and can smoothly switch between the two output states. Based on this, this article analyzes the conditions for achieving load independent constant current and constant voltage output in a bilateral LCC topology, and provides a parameter design method. In response to the possibility of random displacement in different directions in the system, a bidirectional coaxial planar coil structure is adopted, where the primary coil is composed of two coils wound in opposite directions, inner and outer, in series. The proposed EV wireless charging system has the ability to simultaneously achieve constant current/voltage output through simulation and experimental verification, and can still achieve stable output under multi-directional offset conditions.

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