Wireless Power Transfer System for Long-term Sensor on Rotating Plane

This paper presents a wireless power transfer system (WPT) for long-term sensor rotating around an axis on a plane. The system is suitable for powering long-term sensor and does not need to replace the battery periodically. By designing a new type of magnetic coupler, the coupling coefficient between the receiving coil and the transmitting coil can be maintained in a certain range. On the transmitting side, six planar spiral coils are evenly distributed in a circular array, so that the magnetic field on the path of the sensor is always strong. On the receiving side, two planar spiral coils are partially overlapped. The magnetic field generated by the magnetic coupler is analyzed theoretically and simulated by finite element method. The experimental results verify that the WPT system can continuously supply power for 5W load during rotation.