The Combined Effect of Moisture, Temperature and Conducting Particles on the Discharge Behaviour of Sulphur Hexafluoride

Abstract

DHPeng Department of EJedrlcal EngIneering, Huazhong UnlVf!tSity 0/5dence 9 redltlOiogy ZYLI Department 0/ Bedrlcal Engineering, Huozhong University ofScience 8 Technology J M K MacAlpIne MA PhD Department 0/Electtfcal Engineering. Hong Kong Potytechnlc unIversity Measurements have been made Of dc corona onset and breakdown voltages for both positive and negative point/plane eledrode systems in compressed sulphur hexafluoride in the presence of water vapour. The presence Of moisture lowered the onset voltages and raised the breakdown voltages significantly. The effect af maisture onflashover voltages in the presence of metallic particles was also Investigated and the results showed that there was little effed except when moisture was likely to be condensing of the spacer surface; If the moisture froze there was again little effed.The redudlon In flashover voltage due to moisture was Independent Of and In addition to the effed Of the presence Of a metallic particle.