Coreless power supply rails compatible with both stationary and dynamic charging of electric vehicles

A universal wireless power transfer (U-WPT) system which can be used for not only roadway-powered electric vehicles (RPEVs) but also stationary charging of electric vehicles (EVs) is newly proposed in this paper. Contrary to previous WPT systems for RPEVs, the proposed U-WPT can also be used for pick-ups fabricated by the SAE J2954 standard for stationary charging. The proposed U-WPT adopts a new coreless power supply rail to increase its operating frequency from the conventional level of 20 kHz to 85 kHz, as specified in the SAE J2954 standard. With the adaptation of U-WPT, EVs in the future will simply be called wireless electric vehicles (WEVs) regardless of whether they use stationary or dynamic charging systems. A detailed comparison between coreless and with-core power supply rails is thoroughly made, with the results verified in simulations and experiments. This comparison shows that, with the same power rating, the proposed coreless power supply rail is superior to the conventional with-core power supply rail due to its low cost, less insulation voltage stress, lack of core loss, and only slight sensitivity to lateral misalignment, mitigating the condition of less induced voltage.