Study on Energy Harvesting of Open-close Current Transformer

In order to solve the power supply problem of the online monitoring sensor of the high-voltage transmission line, this paper has conducted a study on the energy harvesting of an open-close current transformer (CT). According to the principle of CT induction, the relation between output power and resistor is derived. The silicon steel was selected as magnetic core material by calculating the effect of air-gap size on the initial permeability of different core materials. And a bleeder circuit is designed to solve the problem of CT saturation when the primary current is large. In order to verify the feasibility of the derivation, several simulation has been performed using Saber. Finally, the experiment device is set up and the results showed that the open-close CT could stably output power of 0.5 W when primary current is between 18.6 and 500 A, meeting the demand of sensor power supply.