Research on High Degree-of-Freedom WPT Systems Based on Dipole Coil

Wireless power transfer (WPT) technology achieves complete electrical isolation between power supply and electronic load. It has attracted worldwide attention due to its advantages of safety, reliability and flexibility. However, limited transfer distance and low transfer efficiency have always restricted the further application and promotion of WPT technology. In this paper, the WPT systems based on magnetic dipole-coil structure are proposed, the system has a multi-directional wireless power transfer (MD-WPT) ability within 360erange though optimizing design of a long-bar ferrite core. The optimum design method has been provided and equivalent circuit of the MD-WPT is given for better analysis. The electromagnetic properties of ferrite core in the dipole-coil multi-directional WPT systems are also studied. The power transfer efficiency of the dipole-coil MD-WPT systems can be in-creased by more than 75% and the output power is more than 45W when the ratio of transfer distance to coil length is 1, which can greatly improve the power transfer efficiency and the degree of freedom of power supply. The research results can provide valuable guidelines for multi-directional WPT technologies in the fields such as unmanned aerial vehicle, portable devices, and Internet of Things in the future.