Distance protection coordination using search methods

In this paper, a methodology for calculating the setting impedance of zones 2 and 3 of distance relays is presented, The aim is to reduce protection coordination problems during fault occurrence and changes in the network configuration. The proposed method is based on the impedance seen by the distance relay when faults are simulated on adjacent nodes. The coordination and relay setting is obtained by means of computational algorithms developed to analyze the network topology, determine the pair of primary-backup relays and short circuit studies considering several types of faults in the power system. This process is carried out in an object oriented environment which allows a flexible approach to the user of the software. In the development of this tool search methods based on graph theory were used. The method was applied to an IEEE 14 nodes test system with satisfactory results.