Rotating wireless power transfer: A new concept for wireless charging systems

Abstract

Fast and safe charging are current concerns in relation to wireless charging of autonomous guided vehicles (AGVs). Wireless Power Transfer (WPT) is a capable solution and a replacement for conventional contact-based methods. However, resonant inductive and capacitive WPT topologies demand more power as the gap between transmitter and receiver pads increases. These structures, initially developed for electric vehicle applications, do not adequately optimize power transfer and power quality for the smaller surface areas of AGVs. In this paper, a novel topology for wireless charging concept is described and validated. This methodology has been named rotating WPT, with a primary side spinning neodymium magnet disc. The receiver pad is composed of a circular coil with ferrite U-cores. Calculations of the induced voltage over the rotating magnetic field resulted in 1.95 V at an operating frequency of 2.7 kHz. FEM simulation results show approximately 3 V, while laboratory experiments outputted 33 mV at 3.8 kHz. A sinusoidal waveform was observed from prototype, and power was successfully transferred to the receiver end, validating this proposed topology. This novel WPT system has no inverter, rectifier, nor compensation, decreasing reactive power, assembly costs and complexity while transferring power and enhancing power quality.© 2017 Elsevier Inc. All rights reserved.

Keywords

• Automonous guided vehicles
• DC motor
• Permanent magnets
• Wireless power transfer