【摘要】 硅橡胶复合绝缘子的憎水性迁移特性使其污层具有憎水性,污层中盐分的溶出和流失过程都变得复杂。绝缘子的污闪特性与表面污层受潮时溶解并参与导电的盐分紧密相关,对有效附盐密度(effective equivalent salt deposit density,EESDD,标记为ρEESDD)进行了更深入的研究。用溶出盐密减去流失盐密来表征有效附盐密度,通过试验研究了憎水性迁移时间和绝缘子表面灰密对ρEESDD的影响,以及自然积污绝缘子受潮过程中的ρEESDD。结果发现:绝缘子受潮时ρEESDD先增大后减小,最终趋于稳定;污层憎水性导致受潮时有效附盐密度的变化过程持续时间更长;灰密的增大会导致有效附盐密度的最大值更晚出现;自然积污绝缘子ρEESDD的最大值仅为污层总等值盐密的15%,说明较低的等值盐密也是复合绝缘子污闪电压高的原因之一。更多还原

【Abstract】 Silicone rubber(SR) insulators have excellent hydrophobicity transfer performance, which makes the pollution layer be hydrophobic. Both the process of salt dissolving out of the pollution layer and running off from the surface of insulators would be more complicated for SR insulators. The pollution flashover characteristics are tightly related to the residual dissolved salt which made contribution to the surface conductivity of insulators. The concept of effective equivalent salt deposit density(EESDD, marked as ρEESDD) was studied further. In this paper ρEESDD was characterized with the amount of dissolved salt minus the amount of ran off salt. The influence of hydrophobicity transference time and non-soluble deposit density(NSDD, marked as ρNSDD) on ρEESDD was studied by experiment. ρEESDDof naturally polluted insulators was also studied as comparison. Test results indicate that ρEESDD of SR insulators increased in initial half period and decreased in ending half period of the wetting process. Hydrophobicity of pollution layer made the variation period of ρEESDD last for longer time. Rising of ρNSDDdelayed the time corresponding to maximum value of ρEESDD. For naturally polluted insulators, maximum percent of ρEESDDwas about 15%. It can be inferred that the lower ρEESDD was another reason why SR insulators have higher pollution flashover voltage.更多还原