Energy Harvesting Method of Insulated Ground Wire Based on Self-excited Magnetically Controlled Reactor

Harvesting energy from the insulated shield wire with tuning is expected to be a possible solution to the problem of high power supply for online monitoring devices on high-voltage overhead transmission lines. However, the tuning reactor used to harvest energy in insulated ground wire has a small inductance adjustment range, which is difficult to adapt to the fluctuation of equivalent parameters caused by external conditions. In order to improve the load adaptability of the energy harvesting system and the harvested power of the energy harvesting system, this paper studies a magnetic control reactor with self-excited function, which can actively adjust the reactor inductance according to the fluctuation of the equivalent parameters of the energy harvesting circuit. Firstly, based on the multi-conductor system model and the Thevenin theorem, the topological structure and equivalent model of ground wire tuning energy are established. Secondly, taking the energy collection section of 220 kV high-voltage overhead transmission line as an example, the variation range of equivalent parameters is considered when the line is affected by extreme weather conditions such as icing jump and wind deviation, and the body structure of the line is changed, so as to determine the adjustment range of the inductance value of the tuning reactor for reactor parameter design. Finally, the field-circuit coupling transient simulation is carried out by ANSYS Maxwell to obtain the maximum harvested power and the voltage across the reactor under different conditions. The simulation results show that the proposed magnetically controlled reactor can obtain energy as much as possible from the insulated ground wire when the equivalent parameters of the high voltage overhead transmission line and the load change, and effectively limit the voltage within the allowable value of 30 kV insulation level.