Methodology for the Determination of Real-Time Dynamic Line Ratings for Secure Operation of Overhead Conductors

Dynamic thermal ratings for overhead conductors enable increased loadability of transmission lines during weather conditions that are favorable for conductor cooling. This could provide several benefits, including the accommodation of extra variability and uncertainty in line flows occasioned by increased penetration of intermittent renewable energy sources (IRES) in power networks. However, there are concerns over perceived increased risk of violating thermal limits if prevailing ambient weather conditions are worse than the forecasted values used to calculate the real-time ratings. This paper develops a methodology for the determination of safety factors to be applied in the calculation of real-time dynamic line ratings in order to ensure safe operation of transmission lines. Analyses using real-time weather data show significant increases in line loadability even with the application of the safety factors.