To investigate the relation of life-span and working reliability of a capacitor

repeatedly charge and discharge aging test was conducted on a pulse capacitor for measuring its local direct current partial discharge at different stages of life-span.Three curves of life-span versus maximal discharge magnitude

mean discharge magnitude

and mean discharge frequency were obtained.The morphologies of the capacitor film surfaces at different stages of life-span were observed by the scanning electron microscopy

and the influence of charge and discharge aging test on the surface topography was analyzed.Moreover

based on the analysis of the capacitor breakdown

the factors that result in the partial discharge performance variation and aging breakdown of a pulse capacitor were summarized

and the key reason for causing the capacitor breakdown was found that some insulation defects exist in the edge area of electrodes.