Optimization Analysis of Wireless Charging System for Monitoring Sensors Overhead the HVPLs Based on Impedance Matching

With the development of the power system automation and the smart grid, intelligent monitoring sensors are widely used in the high-voltage power transmission lines (HVPLs). To ensure the stability and effectiveness of the monitoring sensors, the method of power supply should be solved urgently. In this paper, a three-coil wireless power supply system is proposed by considering the insulation problem. By comparing the insulation characteristics of the HVPLs with configuring the relay coil or not, the feasibility of the three-coil wireless power supply system in the application is validated. On the basis, the impedance matching conditions to achieve maximum efficiency and receiving power are analyzed. Particularly, a method to design the relay coil, used as an impedance matching window, is introduced so that the efficiency and the receiving power can be optimized simultaneously in different application situations. The theoretical analysis is confirmed by both simulation and experimental results.