Study on Series Printed-Circuit-Board Coil Matrix for Misalignment-Insensitive Wireless Charging

A serials PCB coil matrix for UAV wireless charging that can operate effectively under misalignment condition was proposed. The simulation model taking into account the mutual inductance change was built and the impedance characteristic of coil was studied by simulation under different misalignment conditions. Based on dynamic impedance method, the transmission characteristics under different misalignment condition was also studied. The system with transmitting (TX) coil matrix at 3×3 and 4×4, which allowed for 6 cm and 8 cm deviation separately, was compared to analyze the size-match influence between TX and receiving (RX) coils. According to the characteristics of the coil matrix, a ferrite matrix that saves material and improved structure strength was proposed. This new structure was proved a better performance than a full ferrite plate. A final 4×4 matrix PCB coil prototype were made and the experiment verified the design that at different misalignment condition, 31.5 W to 62.7 W wireless charging power was presented.