Design Of Monitoring System For Leakage Current Of Polluted Insulator

The character of leakage current on the surface of the suspension-type porcelain insulator is analyzed firstly. At home and abroad, based on the currently laboratory investigation results and the polluted insulators leakage current performance, we analyze the reasons why the failure occurs at the insulator, compare many techniques of on-line checking insulator faults which are used now. On the basis of studying the parameters that manifest the insulators contamination degree, the system monitoring parameters are confirmed. In this paper, a leakage current measurement system is designed with graphical programming language laboratory virtual instrument engineering workbench. Designs, manufacture and test for hardware and software of the whole system are finished.When signal-conditioning circuit is in consideration, attention is paid to design safeguard circuit and magnify circuit. A data acquisition card with proper parameter is selected according to the signal-conditioning circuit. A real time data acquisition and logging about the succession and big capacitance leakage current is realized. A digital filter is designed to filter high frequency signals. The insulator detecting model based on fuzzy is put forward. In the model, the filtered field date collected by on-line monitor was calculated by fuzzy membership function. And it is processed and analysed by MATLAB neural network tools. In this way it can prewarn or give an alarm on insulators' contamination and humidity state.This system is applied for manually polluted insulator measuring in laboratory, which is proved to be stable and dependable.- We can analyze leakage current and pollution discharge on insulator surface.