Distance relay performance evaluation on series compensated transmission line under faulted conditions

Abstract

A compensated line imposes problems to directional relaying schemes due to Voltage and current inversion situations and operation of metal oxide varistor (MOV) protecting series capacitor, reactance modulation issues .In this paper the behavior of series compensated EHV transmission lines during faults is simulated. The use of series capacitors for compensating part of the inductive reactance of long transmission lines increases the power transmission capacity. Emphasis is given on the impact of modern capacitor protection techniques (MOV protection).A novel methodology is proposed to identify faulty phases based on correlation factor computation. Under various fault conditions the proposed method is tested for its validation. The proposed method is tested on series capacitor compensated transmission lines (SCCTLs) with their different configurations and contingency combinations and performance is observed with transmission line both end voltage profiles. Distance characteristics are also drawn for various zones of protection. Simulation results show that proposed method has identified correct fault location.