Forecasting transient conductor temperatures for dynamic thermal rating of high-voltage overhead lines

Abstract Dynamic thermal rating enables the determination of the maximum ampacity of overhead lines based on real-time weather conditions. Overhead lines can therefore be operated even outside conservatively designed static limits. The current conductor temperature and the prevailing weather conditions are monitored in real time by a line monitoring system. This article shows how these measured parameters can be used to model the transient behavior of the conductor temperature. Of particular interest here are the heating characteristics of the overhead line due to abrupt changes in current. These steps in current amplitude can occur due to events such as line tripping. In this paper, machine learning methods (long short-term memory networks) and analytical calculations are used to model the transient thermal characteristics of a 110-kV overhead line based on measured values, with both approaches showing satisfactory results. The paper provides a comparison of the methods and a summary of the insights gained in the modelling process.