Dynamic line rating protection for wind farms overview of project

A Dynamic Line Rating (DLR) protection relay has been developed which calculates the line rating based on weather conditions. It is applied to Central Networks´ Skegness to Boston 132kV line and co-ordinates with their control system in case the latter fails. DLR is a cost effective alternative to re-inforcing the overhead lines where there is a constraint to the DG connection due to the fixed line ratings. Analysis of the site data shows a close co-ordination between the actual and the theoretical calculations of the conductor temperature. The conservative assumptions made about wind direction and solar radiation are also shown to provide a good safety margin.