Wireless charging technologies for electric vehicles: Inductive, capacitive, and magnetic gear

Wireless charging technologies have emerged as a promising solution for electric vehicle (EV) charging, offering convenience and automation. This paper provides a comprehensive review of the three key wireless charging technologies: inductive, capacitive, and magnetic gear. For inductive and capacitive technologies, the working principle, architectures, topologies, advantages, and challenges are discussed and analyzed considering both stationary and dynamic modes of operation. In addition, the paper introduces and analyzes the concept of mixed wireless power transfer, which combines inductive and capacitive charging systems. Additionally, the study explores the magnetic gear wireless power transfer technology, which leverages the interaction between synchronous permanent magnets to transmit power wirelessly. Various research and development efforts related to these technologies are reviewed considering academia, research labs and industry. A comparative analysis among different technologies is presented, considering key performance metrics such as power transfer, efficiency, cost, and operating frequency was presented. This review paper serves as a comprehensive resource for researchers, engineers, and industry professionals interested in wireless charging technologies for EV charging. It highlights the advancements, trade-offs, and potential synergies among inductive, capacitive, and magnetic gear systems, paving the way for the widespread adoption of wireless charging and the development of self-charging and self-driving EVs.