Solution to directional relaying for double circuit line

Abstract

Protection of double circuit line is more complex than the single circuit. Problems associated with directional relaying for double circuit line during close-in fault, cross country fault, load change and with high resistance fault are addressed in this paper. Conventional directional relaying algorithm uses fault voltage and current phasors to derive the decisions and thus, finds its limitation during close-in fault, load change and cross country fault. In this work a directional relaying scheme using fuzzy logic system is proposed for protection of the double circuit line. This paper proposes a solution for directional relaying of double circuit line combining four features. The technique is evaluated using data simulated with EMTDC/PSCAD for a double circuit line and the dynamic performance of the algorithm is also studied.