Research on Key Influencing Factors of Ferroresonance Fault in Ineffective Grounding System

Ferromagnetic resonance faults frequently occur in low current grounding system in recent years, which seriously affects the safe operation of power equipment and system. In view of the shortcomings that the current ferromagnetic resonance faults are mostly confined to post-treatment, the conditions of Ferromagnetic resonance and its influencing factors are quantitatively compared in order to determine the key influencing factors. Firstly, the factors affecting ferroresonance faults and their mechanism are analyzed, and the fault tree model of ferroresonance is constructed to determine the logical sequence of the factors. Secondly, the sensitivity index is constructed to quantify the extent of the factors, and the key factors are determined based on Petri network. Finally, the Changji distribution network in Xinjiang is taken as an example to study and determine the critical factors. The results show that the neutral point parameter of transformer has the greatest influence on ferroresonance overvoltage fault, and the neutral point DC resistance of transformer takes the second place. Both of them are the fundamental factors affecting ferroresonance fault. The research results have important theoretical reference for the prevention and control of ferroresonance over-voltage fault.