Method for Increasing Sensitivity of the Distance Protection on a 330 KV Double-Circuit Transmission Line

Possibilities of increasing the distance protection (DP) sensitivity are considered for a double-circuit transmission line connected to a substation busbar only with one circuit-breaker in each phase. The DP sensitivity can be increased on such a line using mutual connections of the phase wires along its whole length. The minimal (optimal) number of the connections is found by the proposed calculation method.