Advanced aging failure model for overhead conductors

Aging failure modeling is a fundamental requirement in reliability assessment of any actual power system. The level of model detail can potentially reflect realistic means of reliability indices. In that context, this paper proposes an advanced aging failure model for overhead conductors, incorporating the effects of loading and weather conditions into the unavailability calculation. The Arrhenius life-temperature relationship is used to model the lifetime of conductors as a function of temperature. The life measure of the Arrhenius model is adopted as the scale parameter of the Weibull probability distribution. The approach to estimate parameters of the resulting Arrhenius-Weibull distribution is described in detail. Unavailability calculations are performed using the proposed aging failure model for a distribution test system. The results show that if the maximum continuous operating temperature is exceeded, the unavailability of overhead conductors increases depending on both time period, where the conductor temperature is higher than the threshold, and conductor age.