It is a way of energy transmission from the power supply to the electrical equipment without a direct electrical connection. Unlike the traditional contact power supply mode, wireless power transmission has two important advantages: one is that there is no electrical connection between the electrical equipment and the power supply, which reduces the hidden dangers caused by traditional contact power supply, such as power loss and wiring during transmission. Aging, etc., also greatly improves the reliability, flexibility, and safety of electrical equipment. The second is that it can be transmitted by non-magnetic materials, such as soil, glass, air, etc., in the process of power transmission, reducing the impact of harsh external environments and other uncontrollable factors on power transmission, so wireless power transmission is not is hit by the medium.