Overhead Transmission Line Icing Monitoring Based On Fiber Grating Sensor

Wire icing is the main cause of accidents such as the collapse of towers and broken lines in winter,which greatly restricts the development of the power grid and brings huge economic losses to the country.In order to improve this situation,many scholars began to study the wire ice monitoring technology,making it one of the research hotspots in the power field in recent years.However,most of the existing ice monitoring methods employ sensor measurement based on electrical signals,and the effect is poor under strong electromagnetic interference environment around the wires,and the frequent replacement of the battery results in low work efficiency.This article has carried on the thorough research and simulation analysis to the existing ice coating quality calculation method and the basic characteristic of the fiber grating,proposed an on-line monitoring system based on the fiber grating sensor.The main work is as follows:(1)Analyzed the reason why the previous calculation result of the ice coating quality algorithm was inaccurate.An iterative algorithm for the quality of new ice coating was proposed.The ice coating quality of the wire was calculated by measuring the strain variation of the wire and the accuracy of the calculation was improved.(2)The hardware structure of icing monitoring system for overhead transmission lines based on fiber grating sensing is proposed.The influence of refractive index disturbance and grating length on the characteristics of fiber grating is analyzed.The sensing principle of fiber grating is studied and the strain is obtained.The relationship between temperature and temperature parameters and the reflection wavelength of the fiber grating,the cross-sensitivity of temperature and stress were analyzed,and the influence of the selection of various parameters on the monitoring system was further studied.(3)An optical fiber grating load cell that can effectively overcome the cross-sensitivity of temperature and stress and used for ice monitoring of overhead transmission lines is proposed.When the load applied to the fiber grating sensor is 10 KN,the variation range is 1280 μm/KN,and the effect of temperature change on the performance of the load cell is less than ± 0.39%.As the applied load changes,the center wavelength drift of the grating changes linearly,and the sensitivity of the sensor is 0.1285 pm/N.(4)Completed a set of wire icing on-line monitoring software based on JAVA platform,compiled a variety of display interface and menu,data storage and history analysis and other functions,and analyzed the ice-covered on-line monitoring system.