Spectral analysis of leakage current on contaminated insulators by auto regressive method

This paper presents the results of spectral analysis of leakage current waveforms on contaminated insulators under fog conditions. This is a basic study on the development of a monitoring system for substation insulators under contamination conditions. The spectral analysis of the leakage current waveforms was conducted by the Auto Regressive (AR) method with high resolution and without limitation in number of sampling data. The comparative study was done on the initial values of ESDD and NSDD, the salt-fog density and the applied voltage using the power spectra obtained. The results indicate that the spectral analysis by the AR method is available for the monitoring of contamination conditions of outdoor insulators