In order to realize on-line icing and galloping monitoring of overhead transmission lines

an on-line monitoring method for overhead transmission lines based on phase-sensitive optical time domain reflectometry (Φ-OTDR) is proposed.In this paper

by establishing mathematical models of transmission line

the calculation formulas of conductor sag

galloping frequency and other parameters are obtained through theoretical analysis.Secondly

by building the overhead line online monitoring model

the overhead line galloping test and the icing test are proposed respectively

and the leakage principle is analyzed.The dynamic acquisition characteristics of overhead transmission lines are analyzed

and the online status monitoring scheme of transmission lines based on Φ-OTDR is verified.The test results show that the estimation error of sag is less than 5.8% on centimeter scale

and the estimation error of ice thickness is no more than 10.84% on sub-millimeter scale

which gives an accurate description of transmission line status and provides strong support for early warning of transmission line failures.