Directional Relaying News Today

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 t...

In this paper, an innovative directional comparison bus protection (DCBP) scheme based on fault current superimposed component (FCSC) is proposed. Unlike current differential bus protection (CDBP) methods, conventional DCBP schemes not only need current and voltage signals but their performance can be adversely affected by capacitor coupling voltage transformer transients or large voltage drops at the relay location during close-in faults. Furthermore, it is often not possible to implement DCBP ...