A Comparative Review on the Development of High-Frequency and High-Power Capacitive Power Transfer Technology

Wireless power transfer (WPT) technology can deliver energy from source to load without metal cables, which allows high convenience, intelligence, and safety over the conventional conductive approach. Inductive power transfer (IPT) and capacitive power transfer (CPT) are two mainstream near-field wireless power transfer (WPT) technologies. Particularly, IPT technology is relatively mature with over 100 years of history. Although the newly emerging CPT technology is only proposed in the last 20 years, it has attracted growing attention due to its advantages of lightweight, high misalignment tolerance, and no eddy-current loss on metals nearby, which can be applied where the IPT is not convenient. However, compared to the well-developed IPT technology, CPT technology still faces challenges in insufficient theoretical research, underdeveloped system design methodology, and limited power transfer capability. This paper will review the history of capacitive power transfer technology and summarize the recent progress and the existing state-of-the-art CPT works, which provide an overview of the current status of the CPT system, and aim to boost the development of CPT technology.