Phase-frequency characteristic of zero sequence networks in neutral indirectly grounded power system

In order to study phase-frequency characteristic of zero sequence current after single-phase earth fault occurs in distribution network, this paper starts with the line model of distribution network, and analyzes phase-frequency characteristic of zero sequence impedance for distributed parameter line model. By simulation analyzing, for a single feeder, the factors such as transmission line parameter, length, structure and branch feeder etc can effect on the characteristic from different aspects. Further more, simulation in PSCAD analyzes phase-frequency characteristic of zero sequence network after the single-phase-to-ground fault, and influence of neural grounding mode on the characteristic. The study of this paper provides a research basis for the methods using transient zero sequence signals.