FAULT LINE SELECTION METHOD FOR SMALL CURRENT GROUNDING SYSTEM OF DISTRIBUTION NETWORK

摘要

A fault line selection method for a small current grounding system of a distribution network comprises: assembling resistances, a vacuum contactor, a single-phase voltage mutual-inductor and a zero sequence current mutual-inductor in parallel; when the permanent grounding fault occurs in the small current grounding system of the distribution network, switching the resistances connected in parallel in a set time, and further phase angles of the zero sequence currents on outgoing lines of the substation changing; and determining the fault line according to change characteristic roots of the phase angles of the zero sequence currents.