Factors influencing the accuracy of high temperature sag calculations

Increased thermal ratings of transmission lines are important for operators of transmission lines. While scientific knowledge of thermal phenomena has advanced substantially in the past two decades, little has been done to improve the understanding of the practical effects of the most important factors for practical transmission engineers. This report studies the impact of various factors on line rating by investigating their effect on the sag of a typical transmission line span. The report shows that the effects of many commonly considered factors are smaller than practical error margins, while some omitted factors have much more substantial practical significance