Copyright (c) 2008 All rights reserved. http://works.bepress.com/amedeo_andreotti Recent documents in Amedeo Andreotti en-us Wed, 02 Apr 2008 18:25:09 PDT 3600 http://works.bepress.com/amedeo_andreotti/1 http://works.bepress.com/amedeo_andreotti/1 Tue, 02 Oct 2007 12:05:42 PDT The steady state thermal rating of overhead transmission lines is limited by the conductor`s maximum design temperature, which is related to the maximum sag and the loss of tensile strength of the conductors. Traditionally, this overhead transmission lines rating is computed using a deterministic approach, with reference to severe weather conditions. Thus, the application of this method leads to conservative results resulting in under-utilization of conductors. In this paper, a new method based on an hourly probabilistic index is proposed to predict the line thermal rating for each hour of the day; this index is evaluated using the conductor current limit probability density function (pdf). The method uses Bayesian time series models for the weather parameters (ambient temperature, wind speed and wind direction) and calculates the conductor current limit pdf using a Monte Carlo simulation. The probabilistic index is applied by considering measured weather data of both hot and cold seasons; the corresponding lines ratings are reported and analyzed. Antonio Bracale Transmission