Research On Comprehensive Method Of Small Current Grounding Fault Line Selection Based On Fuzzy Theory

Small current grounding fault is a kind of fault which is very difficult to resolve in the failure of many types of power system.No matter domestic or abroad, this kind of fault has not been given a very good treatments or effective solutions. As the fault current is relatively small and modern power electronic devices are easy to produce harmonics, making the process of troubleshooting become more difficult. In the actual project, there are errors in system and measurement, make the problem more complicated. When study the issue, the variability of fault types and system complexity of the structure bring a huge challenge to R&D staffs.This paper which analysis various existing methods of feature selection lines and inadequate is written to study these issues mentioned above, and the zero-sequence current characteristics of system failure is studied. Built the model of power system by the model with Matlab and Matlab-Simulink library simpowersystems software toolbox to simulate the zero-sequence current characteristics. Then taking the simulation data of fault transient current in each line into Matlab wavelet toolbox to analysis and get the results of characteristics. Taking the method based on fuzzy theory to finish the selection by a comprehensive evaluation of the simulation. Ultimately, find a way to get method or ways to achieve the goal of correct selection.