Modelling the reliability of distribution line structures

Abstract

Distribution and sub-transmission line structures invariably makes use of deterministic design criteria. The reasons are basically ease of application. It is argued that the method can be wasteful of resources and will not always meet the contingencies of the environment. This paper looks at the use of probabilistic methods utilising extreme value theory. The approach is to combine deterministic partial factors (where data is not available) with the probabilistic assessment of wind loads and structure degradation over a design life. The methodology utilises a iterative technique to model the pole strength - load parameters and define the limits of risk. A sensitivity analysis in the form of a case study is presented which compares the two methodologies