Dynamic line rating for wind power

Abstract

Dynamic line rating is a novel technique used to determine the actual value of available power transmission capacity of overhead lines being underestimated by static line rating. Contrary to static line rating method, this approach provides huge technical and economic benefits of transmitting the electrical energy under controlled constraints. Nevertheless, it is of utmost importance to have an accurate knowledge of dynamic ampacity before being practically implemented. Owing to dynamic line rating technique, an overhead conductor is rated on the basis of real-time ampacity. Furthermore, the real time ampacity contributes in combating the growing power transmission demand being observed over highly congested power transmission network. Contrary to dynamic line rating approach, building new overhead lines is a lengthy, expensive, and less reliable option. Another important advantage offered by the dynamic line rating approach is to allow excessive renewable power generation in the electricity network, particularly the wind power due to its correlation with real-time ampacity. Besides, dynamic ampacity and wind power integration, the paper also deals with risk analysis associated with conductor overloading. The risk involves increase in conductor sag as it transmits the power beyond its nominal capacity at a certain temperature. However, in this paper, the dynamic as well as the static ampacity of “VL3” overhead conductor is calculated on the basis of its nominal temperature (50 °C) to avoid the risk of its possible expansion and ultimately the deterioration. In addition to technical analysis, the economic analysis of integrating a 60 MW wind park with Fortum's 130 kV regional grid and of applying dynamic line rating approach on a periodically overloaded “VL3” overhead conductor is thoroughly investigated in this research work; to further know how beneficial it is to temporarily postpone the rebuilding and/or construction of a new overhead line in parallel to the existing overhead conductor (VL3).