Effects of ZnO sputtering Layer on Surface charge and Surface discharge of Oil-impregnated Paper

摘要

In order to accelerate charge dissipation and improve the surface discharge characteristics of oil-impregnated paper, a novel method to modify the surface property of the insulating paper applied in converter transformers is presented in this paper. The papers used in the experiment were sputtered with ZnO for different sputtering time of 0, 7.5, 15 and 30 min. The surface morphology of dry paper was observed by scanning electron microscopy, surface and volume conductivities of the oil-impregnated sputtered paper were measured. Moreover, the surface potential decay rate and trap distribution of sputtered papers under voltage with different polarities were studied further by means of surface potential decay (SPD). Finally, the direct current (DC) surface discharges were investigated. Obtained results showed that sputtering with ZnO had an obvious influence on the surface structure of the paper, resulting in an increase of the surface and volume conductivities. The treatment was shown to cause acceleration in the charge decay process. Furthermore, appropriate sputtering enhanced the surface discharge voltage.