Dynamic line rating forecastability for conservative day-ahead line rating values

Dynamic line ratings (DLR) can increase power transmission capacity of power lines. The use of DLR becomes effective, if DLR is possible to be known beforehand, e.g., a day-ahead for the different hours of the following day. Power line ampacity, and thus DLR, is dependent on weather conditions, mainly wind and temperature - in this order of significance. Thus, DLR can be forecasted based on weather forecasts. Temperature, being less variable and more predictable than wind, is used as the only weather variable for DLR forecasting in the method and data analysis presented in this paper. Temperature measurement and forecast data within a cross-border connection area between Finland and Sweden are analyzed for DLR application and DLR forecastability. The presented approach is proven to be sufficient for conservative and high-reliability demanding DLR forecasts, still enabling even significant increase in line ratings most of the time compared to the static line ratings.