Research on Orientation of Ground Fault in Distribution Networks Based on Correlation

Aiming at the insufficiency that the single-phase earthing fault orientation method based on distribution terminal units (DTUs) and fault indicators (FIs) can only monitor the current, an orientation method solely by three-phase fault transient current is proposed. Firstly, in the upstream and downstream sides of the fault location, the direction between the transient current of the fault phase and the healthy phase is theoretically analyzed. Then, a directional criterion based on the correlation between the high-frequency component of the sum of the two-phase transient fault current and the high-frequency component of the other-phase transient current is skillfully established. The effectiveness of the criterion under the influence of some factors is verified by simulation analysis. Results of the analysis and simulation indicate feasibility of the proposed algorithm.