"A Fault Direction Estimation Scheme for Transmission Lines based on Fa" by Amin Jalilian, Amin Rajabi et al.
Conventional directional relaying algorithms use the phase angle difference between the voltage and current to detect fault direction. In series compensated transmission lines (SCTLs), due to the presence of series capacitance in the fault loop, voltage and current inversion phenomena can occur, and, for faults close to the relay location, the voltage amplitude is almost zero. Moreover, subsidence transients of coupling capacitor voltage transformers (CCVT) during close-in faults can challenge the security of directional relaying. In such conditions, conventional directional relaying methods f...
Source: uow.edu.au