Line Selection Strategy for Single-phase Grounding Fault in Distribution Network Considering Bidirectional Power Flow

Single-phase grounding fault is the most common fault in the low current grounding system, and its fault characteristics are not significant and easy to be interfered. On the other hand, distributed power is developing rapidly and widely used, but the research of single-phase grounding fault line selection in distribution network with bidirectional power flow is still needed to be developed. Therefore, how to select the fault line in the distribution network with bidirectional power flow quickly and accurately is very important. So, this paper presents a comprehensive line selection scheme which combines the fifth harmonic method, the group amplitude and phase method, and the polarity comparison method. In this method, the fifth harmonics of fault components are extracted by fast Fourier transform and the lines are selected by comparison. A small current grounding system with bidirectional power flow is established in the simulation environment of PSCAD, and the sensitivity and accuracy of this scheme are verified when single-phase grounding faults occur at different positions in the system.