Test evaluation for life cycle investigation of Wayside lightning arrester in electric railway

Lightning arresters are deteriorated by repetition of protective operation against overvoltages or impulse currents in environments of its use. If a deteriorated arrester is left in power lines, it can lead to an accident such a line to ground fault even in a normal system. Therefore it is necessary to eliminate the deteriorated arrester in advance by checking the soundness of arresters on a regular basis and to ensure the reliability of power systems by preventing accidents. Various deteriorated diagnostic techniques and devices are suggested and most of which measure leakage current components as an indicator of arrester aging. However the techniques based on the magnitude of leakage current measure simply RMS or peak value of leakage current components and do not provide detailed information needed in the diagnosis. In this study, there are several kinds of arrester installation sites in electric railway. From the experimental results, we found out particular phenomenon, proposed a predictive methods properly to each sites, and confirmed that the proposed technique exactly show the deterioration of arrester