A Link-Independent Hybrid Inductive and Capacitive Wireless Power Transfer System for Autonomous Mobility

A link-independent hybrid wireless power transfer system (HPT) that uses both capacitive and inductive action for autonomous vehicle charging application is presented in this article. A three-leg inverter topology is utilized here. Two legs of the inverter, switched at 85 kHz, are used for inductive wireless power transfer (IPT) and the third leg, switched at 1 MHz, is used for capacitive wireless power transfer (CPT). The three-leg inverter module is realized using SiC and GaN switches. The dual switching frequency operation of the converter enables independent compensation techniques to be adopted for IPT and CPT, bringing the modularity feature in the HPT. The circular inductive-link outer diameter is 460 mm and the parallel plate capacitive-link dimension is 600 mm × 600 mm. The power transfer distance or air gap is 100 mm between both links. The output power ratio of IPT to CPT is 2:1. The effectiveness of the proposed topology is validated experimentally. The advantages of this HPT system are modular-link architecture, improved misalignment performance, and distinct frequency of operation for each link that allows the inductive link to meet the SAEJ2954 standard frequency limits compared with the existing HPT systems proposed for electric vehicle charging to support autonomous mobility.