A WPT System with Wide-Range Voltage Gains and Soft Switching via Primary-Side Hybrid Modulation

Wireless power transfer (WPT) systems for electric vehicles (EVs) require wide-range voltage gains to satisfy battery charging requirements and coupling coefficient variations. However, existing solutions typically require additional DC-DC converters, or may suffer from discontinuous output voltage and hard switching. To solve these problems, this paper proposes a primary-side hybrid modulation method that can achieve wide-range voltage regulation and zero voltage switching (ZVS) simultaneously. Atfirst, the topology of the proposed system and the hybrid modulation method based on variable frequency (VF) modulation are presented. Then the design procedure of the system is described, and a new parameter design method of the vehicle assembly is proposed to achieve ZVS and a wide range of operating frequencies.Meanwhile, the control scheme of this system is demonstrated in detail. Finally, a 5-kW prototypewith a maximum efficiency of 93.2% is built and the feasibility and effectiveness of the system are verified.

面向电动汽车（electric vehicles, EVs）的无线电能传输（Wireless power transfer, WPT）系统需要具备宽范围电压增益能力，以适配电池充电需求与耦合系数波动工况。然而现有解决方案往往需要额外配置直流-直流变换器（DC-DC converters），且易出现输出电压不连续、硬开关的缺陷。针对上述问题，本文提出一种原边混合调制方案，可同时实现宽范围电压调节与零电压开关（zero voltage switching, ZVS）。首先给出所提系统的拓扑结构，以及基于变频（variable frequency, VF）调制的混合调制方法；随后阐述系统的设计流程，并提出一种新型车载组件参数设计方法，可实现零电压开关与宽工作频率范围；同时详细论证了该系统的控制方案。最后，搭建一台额定功率5 kW、最高效率达93.2%的实验样机，验证了所提系统的可行性与有效性。