Analysis of spatial and seasonal distribution of power transmission line thermal aging

Aging assessment of conductors and other components of electric power networks plays an important role in operation and asset management of power transmission systems. Conductors can lose their tensile strength due to the adverse effects of conductor aging caused by thermal overload, and subsequent annealing. This paper analyses seasonal dependency of the thermal aging using known characteristics of transmission conductor, along with load information and weather data. Weather conditions are derived from historical weather reanalysis and interpolated to locations of the transmission lines. By analyzing the conductor temperatures, aging due to loss of conductor tensile strength is estimated at individual locations along the transmission corridor. This paper is concerned with analysis of spatial distribution of thermal aging along the line for different seasons. The proposed methodology is illustrated using a case study analyzing a power transmission line in interior British Columbia, Canada. The simulation results show strong seasonal dependency of both, thermal aging and transmission capacity. This information is important for transmission network operating procedures, e.g. scheduling of line inspections, maintenance, or reconductoring, and for effective transmission asset management.