Design and Implementation of Electric Field-Induction Based Energy Harvesting System for High Voltage Power Transmission Lines

High-voltage transmission line online monitoring device can effectively promote the safety and stability of the power system, thus acting as an important part of the smart grid. However, for practical applications, the power supply problem is always the key limitation that restricts the development of online monitoring device. To provide stable and reliable power supply to the online monitoring devices, a space energy harvesting system based on the electric field induction is proposed to pick up power from the high voltage (HV) electric field around the transmission lines. Firstly, the system structure is demonstrated, with the analysis of the system’s working principles. Then, the coupling plates for space energy harvesting is optimized, with the use of frame-shaped plates to seek a balance between the power level and the system sizes. Furthermore, based on the system’s quasi-current source characteristics, a DC/DC converter is designed to notably improve the output power level. Finally, with respect to the discontinuous power demand of the on-line monitoring device, a hysteresis discharge mechanism is designed. Both the theoretical and the experimental results show that the system is able to output more than 25mW power stably. With the use of energy storage module, the on-line monitoring device is able to upload the picture information every two hours.