Impact of the dynamic line rating analysis in regions with high levels of wind and solar PV generation

Power system operators traditionally use a static transmission line rating method to ensure the electric grid operates under a pre-defined limit temperature of the conductors. This method normally assesses the maximal power capacity of each line using conservative constant weather conditions that usually underestimate the real transmission capacity of overhead power lines. Dynamic line rating (DLR) analysis represent a safe and cost-efficient way to deal with existing congested networks and allowing further integration of current/future renewable generation in many regions.This work applies a DLR tool to identify the power lines' additional theoretical capacity obtained by using this methodology for two Portuguese regions with distinct conditions regarding i) weather, ii) topography and iii) wind and solar power resource. The capacity values obtained are presented, and a comparison with the traditional values obtained from the static methodology used by the Portuguese system operator is established. Results show that the dynamic approach enables significant gains in the line rating for both regions and its use can be extended to regions with high solar resource since the induced cooling effect is also observed in those regions.