Identification of critical aging segments and hotspots of power transmission lines

Abstract

Localization of hotspots and critical aging segments of transmission lines is important for operation and asset management of power transmission systems. Conductors can lose their tensile strength due to the adverse effects of conductor aging caused by annealing. Although the loss of conductor strength is gradual, it accumulates over time and increases the probability of outages and blackouts. Therefore, it is important to keep track of conductor temperatures over time and in space, in order to identify segments of power transmission network that may require more close attention, repairs, or reinforcements. This paper describes and illustrates a new methodology for localization of hotspots and identification of critical aging segments of power transmission lines. The methodology uses load information and weather conditions derived from historical weather reanalysis to derive a time series of spatially resolved map of conductor temperatures. The temperature map is then used to estimate loss of conductor tensile strength for each span of the transmission line. The process is illustrated for a sample transmission line, using assumed load current and historical weather information spanning a period of five years. The simulation results show that the proposed approach provides information vital for transmission network operating procedures and transmission asset management.