Impact of Dynamic Line Rating on Power Systems

Continuously increasing electrical demand, together with national renewable energy targets, has resulted in an increase in the amount of renewable generation being connected to the bulk power system. Therefore, the existing transmission/distribution network becomes the critical limiting factor which may constrain generation during arduous loading condition and/or system contingency. Due to the difficulties in obtaining permission for network expansion, a possible solution is to maximize the utilization of existing network by employing dynamic line rating (DLR), which determines line ampacity based on real time weather conditions. Based on the weather and loading data collected from Northern Ireland Electricity Network, the extra power facilitated by DLR is quantified. Then, the impact of uprating transmission lines on a power system is tested on both the IEEE Reliability Test System and a single line representation. Finally, the improvement using DLR on load flow calculations is introduced, which takes into account the temperature dependent line resistance for the power system load flow calculations.