Probabilistic approaches to transmission line thermal ratings

The utilisation of overhead line ratings enhanced as a result of statistical considerations has brought significant benefits and suggests further enhancements are possible. Weather parameters and, more particularly, derived overhead line current carrying capabilities cannot be represented accurately by `standard´ distributions. Differences in weather around the country may permit the enhancement of ratings in some areas. The use of weather forecasts to predict temporary increases in ratings and thereby relax some of the transmission constraints on economic generation dispatch is a possibility which merits investigation. The feasibility of the concept will largely hang on a probabilistic risk/benefit analysis