Advanced transmission line protection system

This paper describes an advanced protective relay system for high-speed transmission line protection. In the paper, we present the high-speed distance element performance, an algorithm that prevents the zone 1 element overreach in series-compensated transmission lines, and a reliable frequency estimation algorithm for correct frequency tracking during pole-open conditions to prevent relay malfunctions. Finally, we present logic that prevents distance element polarization corruption during any pole-open condition in single-phase tripping and reclosing applications.