Design and Experiment of a Reconfigurable Magnetic Resonance Coupling Wireless Power Transmission System

Magnetic resonance coupling wireless power transmission (WPT) provides a safe and efficient power supply for small household appliances and implanted devices, but the tolerance of the transmission distance is poor. To improve the robustness of the transmission distance of the magnetic resonance WPT system, a method of using a reconfigurable helical coil array is proposed. Compared with the traditional four-coil structure of the same volume, different source and load coils are selected under distinct distance conditions. The coupling coefficient between the coils is changed to increase the stability of transmission efficiency and distance. To avoid the mechanical movement, all source and load coils have been adjusted at fixed position. Moreover, a control method is introduced to achieve coil switching. The experimental results show that the transmission distance of the proposed system is increased to 1.75 times of the coil diameter, while the efficiency remains above 70%.