Publication

Abstract : Protection of the series capacitor compensated transmission line is a very challenging task due to the abrupt change in apparent impedance seen by the relay, voltage inversion and current inversion phenomena. This paper presents a combined discrete Fourier Transform and fuzzy system based solution to protection issues of the SCCTL. Fuzzy inference system have been considered for detection of the existence of fault in a SCCTL and also to recognize its direction whether forward or reverse fault. The presented fuzzy based direction relaying scheme avoid the requirement of a communication link as it uses only single end measurements. The presented scheme has been corroborated for all 10 types of shunt faults that may occur in a transmission line under different fault inception angle , fault resistances and fault location . Feasibility of proposed scheme is evaluated in a 735 kV; 60 Hz transmission system with midpoint series capacitor compensation using MATLAB Simulink platform. The presented technique needs current and voltage signals obtainable at one end of transmission line. The presented fuzzy-based relaying algorithm can identify the existence of fault in forward or reverse path in ≤8.87 ms time and the test results corroborate its reliability, accuracy and security.