Design and field experience of a dynamic line rating protection

This paper describes how dynamic line rating is applied for load management and protection on transmission lines thereby enabling a larger penetration of wind generation. The rating of the line is calculated dynamically from local weather measurements to co-ordinate allowed generation automatically. As a back-up system, in case for some reason the wind farm power output is not reduced on command by the control system, a relay is available to initiate tripping of the wind generators. The paper outlines the design of the relay, presents two different utility applications and includes an analysis of the field data gathered from site which is used to verify the accuracy of the relay algorithm.