Development of Power Source for Underground Cable Online Monitoring System

In order to solve the power supply problems of the wireless network on-line monitoring system of underground power cable, an energy-harvesting coil, which uses the magnetic field around the cable, was developed. The energy harvesting coil using Mn-Zn ferrite material of high initial permeability as its core, is designed to be cylindrical structure, which can be applicable to the power cables with different voltage levels. Through the theoretical calculation, software simulation, and the experiments, the structure of the harvesting coil, the core material, the number of coil turns, and the output circuit management can be confirmed. In this way, 35kV underground power cable can be safely operated within the range of 20-700A, with the output power of 25-100mW.