The Detecting System and Method of Quasi-Distributed Fiber Bragg Grating for Overhead Transmission Line Conductor Ice and Composite Insulator Icing Load

Abstract

Transmission lines icing is destructive to the operation of the power grid. There is a lack of methods to monitor overhead transmission line conductors and insulators for icing load simultaneously. In this paper, we implanted six optical fibers with three quasi-distributed FBGs each into the interface of a 110kV composite insulator and built an icing detection system, and proposed three ways for measuring overhead transmission lines icing load. A method for quasi-distributed FBG to differentiate between the measurement of running insulator umbrella and conductor icing load was proposed and validated. The effect of the number of implanted optical fibers on the measurement accuracy was studied. The results show that the relative error of simulated insulator umbrella skirt icing load measurement is -7.3%∼-2.7%. The 200m-span running conductor insulator umbrella skirt icing load measurement relative error is -11.5%∼-3.8%; the relative error of conductor ice measurement is -16.5%∼9.0% and absolute error is -0.83∼1.5mm. The composite insulator with an optical fiber embedded can accurately warn of serious icing on the conductor, with two can achieve the conductor icing measuring absolute error of about ±1mm. As for accurately measuring both the umbrella skirt and the conductor icing, it is necessary to implant six optical fibers.