Root-Cause Identification of Single Line-to-Ground Fault in Urban Small Current Grounding Systems Based on Correlation Dimension and Average Resistance

Root-cause identification of faults in a distribution network is conducive to fault inspection as well as reducing injuries and damage. In this article, a novel method based on correlation dimension and average resistance is proposed to identify the root cause of permanent single line-to-ground fault in urban small current grounding systems. First, the reliability of the grounding fault and whether the fault occurred on a dry or wet surface can be identified by the correlation dimension. Then, the average resistance of the fault is used to classify the specific root cause, including wet land, dry land, wet concrete, dry concrete, and water. Experimental results show that this method can realize the classification of root causes and is robust to sampling rate, harmonics, and line impedance.