Limiting sensitivity of location probing of power transmission lines while detecting ice coatings

Ice coatings on power transmission lines (PTSs) are detected during location probing from the amplitude reduction and the increase of propagation (delay) time of the reflected signals. The stability of the amplitude and delay of the reflected signals in the normal conditions in the absence of glaze ice and the limiting sensitivity of the method of location are studied in the article. As a result of long-term measurements on operating power transmission lines, the daily–annual variation of amplitude U and delay Δτ of the reflected signals were detected due to the high sensitivity of the method of location, which is mainly due to variations in environmental temperature. It was shown that these variations, combined with the random fluctuations,in normal conditions are much smaller than the changes of the amplitude and delay of signals upon early appearance of ice coatings. The recommendations on selection of the values of settings (operating threshold) are given by the amplitude and delay upon detection of the glaze ice and damage to the power transmission lines by the method of location. © 2016, Allerton Press, Inc.