D24.6 - Class E/EF Inductive Power Transfer to Achieve Stable Output Under Variable Low Coupling

Thursday, March 20, 2025

11:30 AM – 1:30 PM ET

Location: Level One, Hall A3

Technical Dialogue Presenter(s)

YZ

Yifan Zhao

University of Cambridge

Presentation Paper

Co-Author(s)

Mowei Lu

University of Cambridge
HL

Heyuan Li

ShanghaiTech University
Minfan Fu

ShanghaiTech University
ZZ

Zhenbin Zhang

Shandong University
SG

Stefan M Goetz

University of Cambridge

This paper develops a stable output power inductive power transfer (IPT) system based on a Class- E/EF inverter as a load-independent circuit that has recently attracted widespread interest. However, applying this design to IPT systems has proven challenging due to its high sensitivity to minor coupling variation. To address this issue, this paper uses an expanded impedance model and substitutes the secondary side's perfect resonance with a detuned design. Therefore, the system can maintain stable output even under low coupling variations. A 400 kHz experimental prototype was constructed to validate these findings. The experimental results indicate that the output power fluctuation remains within 15% as the coupling coefficient varies from 0.04 to 0.07, with the peak power efficiency achieving 91%.