Predictive reliability assessment of distribution systems including extreme adverse weather

The physical environment in which a distribution system resides has a major effect on the resulting reliability of the network. The physical stress placed on system components can be much higher in bad weather than that encountered under normal weather conditions. The conventional approach to incorporate bad weather in the predictive assessment of redundant transmission line facilities is to divide the overall weather conditions into the two states of normal and adverse weather. This paper illustrates the conventional approach to predictive reliability assessment using a two-state weather model and extends these concepts to recognize extremely adverse weather conditions. The resulting three-state weather model is presented and analyzed to illustrate the applicability of the model and the impact of dividing bad weather into the two categories of adverse and major adverse weather.