Line Selection of Single-Phase Fault Grounding System Based on the Deviation Criterion of Composite Zero-Sequence Admittance

The current methods for line selection of small current fault grounding system faults within distribution networks have some limitations. This paper proposes a method based on the deviation criterion of composite zero-sequence admittance for line selection of single-phase fault grounding systems with small currents. First, the derivation formula of zero-sequence admittance for small current grounding systems considering asymmetrical transmission lines is presented. Then, a method based on the deviation criterion of composite zero-sequence admittance is proposed for accurate fault line selection. Finally, a fault model is built by using simulation software and simulation experiments are conducted to verify that this method can rightly select the fault line by significant feature values.