Romanian approach of ACSR overhead line conductor end of life using live line tehniques to get samples for testing

摘要

The necessity of estimating the life span left for the ACSR conductors of the overhead electric lines appeared as an actual problem in the 90's, as a following to the fact that their initial average duration, of 40–50 years, was or is going to be surpassed in a lot of instances, because the concept of development used for the energy consumptions was not realistic enough for the whole considered period, especially in as much as the last 25 years are meant. Generally there are three recognized factors that lead to reducing the mechanic characteristics of the ASCR conductors: excessive heating, due to overloading, dynamic mechanic efforts and the corrosive effect of the environment. The analyses of the conductors shape can be made on the lines and in the laboratory. Out of the multitude of the possible tests used for leading to the information about the degree of mechanic degradation in the conductors three types were evinced: qualitative and quasi-quantitative measuring of the zinc coating corrosion on the steel wires that make up the conductor core by using specially conceived devices that move along the conductor of energized or unenergized lines with or without electric tension, the breaking up test by tensioning the aluminum and steel strands of a conductor sample taken from the line. The three mentioned types of tests can be performed by using the specific methods for live- line work.