A New Thermal Rating Approach: The Real Time Thermal Rating System for Strategic Overhead Conductor Transmission Lines Part IV Daily Comparisons of Real-Time and Conventional Thermal Rating and Establishment of Typical Annual Weather Models

For the first time, comparisons are given between the real- time thermal capacity and conventional ratings derived from fixed value weather parameters. If conventional normal ampacity ratings, established from these conservative weather parameters, are applied to system peak day weather conditions, it is shown that the conductor temperature, depending on transmission line azimuth, can be much greater than the allowable limit and line to ground clearances could be reduced. This is primarily due to the absence of wind direction being considered as a relevant parameter in the determination of the conventional rating.