Research on adaptive single-pole reclosing technique for EHV/UHV transmission lines

The character of the voltage at the end of the opened phase conductor was studied and an improved voltage criterion was proposed to distinguish between transient and permanent faults. The performance of the improved criterion is hardly influenced by the load currents of healthy phases, transmission line length, fault distance and fault earth resistance. For EHV/UHV lines with shunt reactors, the improved method is also effective when a calculated capacitive coupling voltage is employed. Simulation tests show that the conclusions drawn in this paper are correct.