An Overview of Resonant Circuits for Wireless Power Transfer

TLDR

Growing safety concerns and the expanding use of wireless power transfer for industrial devices, consumer electronics, and electric vehicles have spurred interest in developing high‑efficiency, high‑frequency resonant circuits for near‑field and far‑field systems. This paper reviews resonant circuit designs for near‑field wireless power transfer, focusing on non‑resonant converters with resonant tanks, resonant inverters, compensation networks, and selective resonant circuits. The review covers non‑resonant converters and resonant inverters with resonant tanks, compensation networks, selective resonant circuits, and discusses key issues such as zero‑voltage switching, zero‑voltage derivative switching, and total harmonic distortion. The study elaborates bidirectional resonant inverters designed for vehicle‑to‑grid wireless power transfer systems.

Abstract

With ever-increasing concerns for the safety and convenience of the power supply, there is a fast growing interest in wireless power transfer (WPT) for industrial devices, consumer electronics, and electric vehicles (EVs). As the resonant circuit is one of the cores of both the near-field and far-field WPT systems, it is a pressing need for researchers to develop a high-efficiency high-frequency resonant circuit, especially for the mid-range near-field WPT system. In this paper, an overview of resonant circuits for the near-field WPT system is presented, with emphasis on the non-resonant converters with a resonant tank and resonant inverters with a resonant tank as well as compensation networks and selective resonant circuits. Moreover, some key issues including the zero-voltage switching, zero-voltage derivative switching and total harmonic distortion are addressed. With the increasing usage of wireless charging for EVs, bidirectional resonant inverters for WPT based vehicle-to-grid systems are elaborated.