Low-Frequency Medium Power Capacitor-Free Self-Resonant Wireless Power Transfer

Abstract

With the rapid development of wireless power transfer (WPT), the self-resonant WPT system without using additional compensation capacitors has attracted attention. However, most of reported self-resonant WPT systems have low power transfer (less than 100 W) and high operating frequencies at megahertz. In this paper, four multi-layer, self-resonant WPT coil pads with different dielectrics are designed and experimentally validated. The aim of this paper is to increase the power rating and decrease the operating frequency for capacitor-free WPT system compared to reported systems used in consumer electronics. Analysis of integrated compensation capacitance, inductance, and parasitic capacitance of the coil is provided. Finite Element Analysis (FEA) is used to evaluate four dielectric materials, mica, polypropylene, polyimide, and fiberglass. An experimental setup has been developed, which can achieve more than 360 W power transfer for a 120 mm air gap with an efficiency of 82% and an operating frequency of near 80 kHz.

Wireless charging system design based on ICPT topology

“…Wireless power transmission (WPT) technology, like wireless communication technology, is free from the boundaries of tangible media [1] . This technology makes the wireless charging device under the parking space charge the battery by the wireless charging as long as the inspection trolley is parked in the designated charging area, which greatly facilitates the equipment power supply, and greatly reduces the transmission of the potential security risks that may arise, with high reliability [2] .…”