Life Assessment of Transmission Line Using Historical Health Index

In this paper, the lifetime of transmission line is estimated by using actual health index (HI) and normal distribution technique. The health index of transmission lines is assessed by using actual technical data, practical testing and visual inspection results. The weighting and scoring method as well as analytical hierarchy process are applied to this assessment. The %HIs are used to determine % HI -curve by applying normal distribution technique while the aging-curve is determined by applying Gompertz-Makeham law of mortality. Both curves are matched to determine the estimated age according to the calculated %HI at individual probability of failure. Forty transmission lines in 115, 230, and 500 kV networks with actual data are performed in this assessment resulting to a proper maintenance planning and risk mitigation.