Omnidirectional wireless power transfer system with multiple receivers and a single wire wound spiral transmitter

Last decade has witnessed dramatic advancements in wireless charging distance of magnetic resonant coupling wireless power transfer (MRCWPT) for various portable electronic devices. Driven by the demand of cost-effective and compact system working for multiple receivers, a novel omnidirectional MRCWPT system with a single wire wound spiral transmitter and a single power source is proposed in this work. Besides, an equivalent circuit model is established to derive the power transfer efficiency (PTE) of this novel MRCWPT system. Finite element simulation results have shown that the magnetic field distribution for the proposed model is uniform in all directions. And the PTE of the system depending on the distance between the transmitter and receivers is demonstrated to be independent of the receiving angles. Finally, the theoretical analysis of the simulation results is verified by practical experimental results, which shows that the PTE of the system reaches 60% at the distance of 160 mm and the resonant frequency of 15.5 MHz. © 2019, Electromagnetics Academy. All rights reserved.