Overhead transmission line health monitoring method and system

Abstract

The invention discloses an overhead transmission line health monitoring method based on a phase sensitive optical time domain reflectometer and a multi-core optical fiber. The method comprises the steps: using the phase sensitive optical time domain reflectometer phi-OTDR as a sensor, using a multi-core optical fiber MCF as a signal transmission medium and a sensitive element of a system at the same time, and enabling the multi-core optical fiber MCF to follow an overhead transmission line; performing segmented interception on a Rayleigh scattering curve obtained by each detection pulse, namely performing segmented interception on optical signals, acquired by the system, of a plurality of cores, and extracting all strain values required by shape reconstruction at one time by using a phi-OTDR detection data analysis system; and calculating the curvature radius of a shape change region of the multi-core optical fiber according to a geometric method for describing a space curve, and obtaining shape reconstruction characteristic values by solving a Frenet-Serret ordinary differential equation, so that the bending degree and the torsion degree of a measured cable can be determined. Comprehensive and real-time health monitoring of a galloping change rule of the overhead transmission line is realized.

Description

technical field [0001] The invention relates to a method and system for health monitoring of overhead transmission lines, in particular to a sensing method and system for comprehensively monitoring galloping amplitude, frequency, galloping track and other information based on distributed optical fiber sensing technology, belonging to Smart grid field. Background technique [0002] High-voltage overhead transmission lines are the main mode of power transmission in my country, but during their operation, galloping disasters will be caused by natural weather such as wind, rain, and snow. Galloping can easily lead to whipping of wires, arc burns, or broken wires and strands. , At the same time, it is easy to cause severe wear, breakage, and shedding of hardware, or breakage of insulator steel feet, toppling of poles and towers, and other faults such as line tripping. [0003] Therefore, it is very necessary to monitor and warn the dance in real time, and to activate the plan to ...

AI Technical Summary

Problems solved by technology

The image collected by the video image method has limited clarity and the output two-dimensional information is difficult to truly reflect the three-dimensional galloping situation of the wire, and is easily affected by weather such as rain and snow; the acceleration sensor can quantitatively analyze the up and down vibration and left and right swing of a certain point of the transmission line , but it can only measure the amplitude and frequency of the linear motion of the wire, and it cannot be accurately measured for complex circular motions, and when the galloping is violent, it is easy to loosen or even fall off, adding unpredictable noise, resulting in serious distortion of the measured galloping trajectory; in addition , the power supply of the above two technologies for long-term outdoor work is limited

Currently, the Fiber Brag Grating (FBG) sensor can only measure the frequency and intensity of wire galloping quantitatively, and it is difficult to estimate the wire galloping trajectory by using the FBG strain variation.

Distributed sensors based on single-core optical fiber are similar to FBG technology, which can only measure the changing frequency and changing intensity of wire galloping, but cannot monitor the spatial torsion and longitudinal fluctuation wavelength of wire galloping

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