Optimal coordination of directional overcurrent relays consideringdefinite time backup relaying

摘要

A methodology is presented for the consideration of definite-timenbackup relays in the optimal coordination of directional overcurrentnrelays using linear programming. It is shown that the influence ofnconsidering second-zone distance relays and breaker failure relaysnimpose important requirements for the determination of the time dialnsettings of directional overcurrent relays. The paper introduces anrevised formulation of the optimization problem. Results are presentednfor the application of the methodology on a power system with 2ngenerators, 9 buses, 2 transformers and 7 transmission lines