A 9 kW 3.47 MHz wireless power transfer system with a parallel differential Class E Inverter for industrial applications
Author(s)
Nikiforidis, Ioannis
Bampouras, Konstantinos
Wagle, Prateek
Yates, David C
Mitcheson, Paul D
Type
Journal Article
Abstract
Wireless power transfer in the low kW power range can have numerous applications in industrial settings, such as powering machinery and charging automated guided vehicles. High frequency inductive power transfer combines lightweight and compact coils with efficient resonant converters resulting in high power density. However, combining multi-MHz operating frequency with multi-kW level power output using conventional half-bridge or multi-resonant Class E type topologies and wide band-gap devices is challenging. In this paper we demonstrate a 9 kW, 3.47 MHz dc to three-phase wireless system that is capable of reliably providing 50 Hz, 400 V mains supply to industrial units that cannot be physically plugged in, over an air-gap of 12 cm. The system is robust over the entire load range, providing a stable output voltage to the load, with 95% dc-dc efficiency over most of the load range. The power density of the inverter is 4.8 W/cm 3 and it can produce over 70 A peak current in the primary coil. This performance is achieved using power-combining Class E type converters with the secondary operating slightly off-resonance to better accommodate the effects of the highly varying load.
Date Issued
2025-08-01
Date Acceptance
2024-11-01
Citation
IEEE Journal of Emerging and Selected Topics in Power Electronics, 2025, 13 (4), pp.4171-4190
ISSN
2168-6777
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Start Page
4171
End Page
4190
Journal / Book Title
IEEE Journal of Emerging and Selected Topics in Power Electronics
Volume
13
Issue
4
Copyright Statement
This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/
License URL
Identifier
http://dx.doi.org/10.1109/jestpe.2024.3497712
Publication Status
Published
Date Publish Online
2024-11-13