A Power Supply Technology for a Low-Power Online Monitoring Sensor Based on Electric Field Induction

In order to provide a safe and stable power supply for low-power online monitoring sensors of transmission lines, a method of harvesting space electric field energy by using the impedance conversion characteristics of the transformer and the reactive compensation characteristics of the capacitor is proposed. The method effectively solves the key problem that the power of energy harvesting based on electric field induction is limited by the transformer excitation reactance and is difficult to upgrade. In this paper, the principle of power supply technology based on electric field induction is described in detail, and the influencing factors such as the wire erection mode, polar plate installation position, and capacitance compensation characteristics are simulated and tested. The test results show that when the power supply voltage is 50 kV, the stray capacitance is 14 pF, the compensation capacitance is 0.86 nF, and the load resistance is 1 kΩ, the energy-harvesting power is 340 mW. Finally, the power supply circuit of a drive-away-birds apparatus is designed, which shows that it can provide a stable and reliable power supply for online monitoring sensors.