Research on the Power Supply System of Ring Main Unit Monitoring Equipment Based on Directional Microwave Wireless Energy Transmission

In order to solve the problems of high maintenance cost and complex wiring of wired cables or batteries used in the operation monitoring equipment of ring main unit, a directional microwave wireless energy transmission system is proposed. Energy transmission is carried out by arranging microstrip patch antenna arrays at the transmitting end and the receiving end. A linear high-gain antenna based on a double-layer metasurface is designed, operating in the 2.45 GHz band, which is much smaller than traditional antennas and suitable for arrangement in the narrow space inside the ring main cabinet. Subsequently, a high-frequency rectifier circuit was designed to meet the requirements of high-efficiency wattlevel power output, and this scheme was experimentally verified. When the transmission distance was 0.4 m, the high-frequency rectifier circuit could output a power of 1.1 w. The experimental results show that this wireless energy transmission system can effectively transfer electrical energy from the transmitting end to the receiving end and output it to the monitoring equipment through the high-frequency rectifier circuit, providing a new maintenance-free and highly reliable wireless power supply method for the ring main unit monitoring equipment.