Dynamic wireless power transfer (WPT) for charging electric vehicles (EVs) overcomes some of the problems associated with EVs battery size and weight as well as distance range limitation and long charging duration. High efficiency and fixed output voltage of WPT systems are of great importance for reducing operating cost and facilitating battery charging, respectively. On the other hand, utilizing the maximum power transfer capability of a WPT system leads to a capital cost saving of the system. In this article, the product of transferred power efficiency and input power factor (η·PF) is regarded as a criterion to make near full usage of the system power transfer capacity as well as reduce the capital and operating cost of the system. An optimal frequency-tracking method is proposed to maximize η·PF of the system taking into account possible abrupt changes in the coupling coefficient of the WPT system due to deviations of EV from alignment with the track along the road. In addition, the output voltage of the system is regulated simultaneously by an on-line adjustment of the primary inverter duty ratio. The optimal frequency-tracking method and voltage regulation are validated by extensive simulation and experimental results.

中文翻译：

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一种用于电动汽车的高效高功率因数动态WPT系统

用于为电动汽车 (EV) 充电的动态无线电力传输 (WPT) 克服了与 EV 电池尺寸和重量以及距离范围限制和充电持续时间长相关的一些问题。WPT 系统的高效率和固定输出电压对于降低运营成本和促进电池充电分别具有重要意义。另一方面，利用 WPT 系统的最大功率传输能力可以节省系统的资本成本。在本文中，传输功率效率和输入功率因数（η·PF）的乘积被视为几乎充分利用系统功率传输容量以及降低系统资本和运行成本的标准。考虑到由于 EV 与沿道路的轨道对齐的偏差可能导致 WPT 系统耦合系数的突然变化，提出了一种最佳频率跟踪方法来最大化系统的 η·PF。此外，系统的输出电压通过主逆变器占空比的在线调整同时进行调节。最佳频率跟踪方法和电压调节通过广泛的模拟和实验结果得到验证。