Research Of Novel High-sensitivity Fiber-optic Current Sensing Technology

Fiber-optic sensing technologies are developed rapidly and have already been used in mechanical processing,aerospace,military defense,petroleum,and mining industry applications due to their great advantages such as immunity to electromagnetic interference,high sensitivity,and high safety.Among of these factors,fiber-optic current sensing technology,driven by the development of smart grid,have becoming more and more important in both scientific research and industrial application prospects.This research propose and develop a fiber-optic current sensing system with high sensitivity based on the Faraday Effect using a recirculating fiber loop architecture.By employing optic switch and recirculation technology,the goals of both improving the system sensitivity and reducing the system complexity have been achieved.The proposed method obtains the current intensity by analyzing the relationship between rotation angle and current intensity.The experimental setup uses the circulation loop with optic switch and a standard single-mode fiber as sensing fiber.The circulation number of pulsed light in the loop is controlled by setting the on-off state of the optic switch.The experiment results show that the system sensitivity can be largely enhanced by increasing the circulation number.By optimizing the system with consideration of parameters such as sensitivity,resolution and stability,a sensitivity of 11.5°/A and a resolution of 10 mA has been achieved,turning out the feasibility of this scheme.After improving the experiment,a sensitivity of 19.8°/A is reached.The proposed method is promising for high sensitivity current monitoring applications with follow-up study.