Study on Fault Line Selection based on Transient and Mathematical Morphology in Resonant Grounded System

Based on morphological filter and correlation analysis, this paper presented a novel transient method for single-phase ground-fault line selection in resonant grounded network. Firstly an improved composite morphological filter with multiple-structure elements (SE) is designed to filtering the transient zero-sequence fault signals. Using it the meaningful information can be derived effectively from the signal interfered by noise. Secondly based on analyzing the transient characteristics of the lines' zero-sequence current and the relationship between them, a novel method using correlation coefficient to determine the faulted line is presented. The results of the verification of proposed method by physical simulation and on- site actual fault data show that the proposed method is practicable.