变压器油对室温硫化硅橡胶绝缘特性的影响(Ⅱ)

Effects of Transformer Oil on Insulation Performance of RTV Silicone Rubber(Ⅱ)

变压器套管由于桩头过热、设计缺陷会导致漏油现象发生,为进一步研究室温硫化硅橡胶(room tempera-ture vulcanization,RTV)被变压器油染污后外绝缘性能下降的机理,采用加速老化试验对不同RTV试样浸油后的外绝缘特性进行了试验研究。模拟RTV在外界环境中不同的浸油及染污过程,对不同方式浸油及染污预处理后的RTV憎水特性的差异进行了分析;借助高精度电子称对不同RTV的吸油和渗油特性进行了对比试验。分析了变压器油对RTV附着力和表面、体积电阻的影响并结合试验数据分析了套管污闪事故产生的原因。结果表明,RTV的憎水迁移特性与染污方式存在较大关系,不同RTV经变压器油浸泡及染污后的外绝缘表现具有一定相似性。经nmSiO2、氟化聚硅氧烷协同改性的RTV对变压器油具有相对较好的"斥性",不同RTV试样浸油前后的附着力表现存在较大差异。

Transformer bushing may seep oil due to trailer coupling overheat or design flaws,in order to research the reasons for decline of external insulating performance of room temperature vulcanization（RTV） after polluted by transformer oil,immersion oil accelerated aging were used to investigate external insulation characteristics of various RTV samples.Different oil impregnation and pollution smudging were accomplished to simulate complex factors of external environment,so various oil immersion and different artificial pre-pollution methods were completed.Differences among different treatment ways of RTV were analyzed.Moreover,oil absorption and evolution contrast tests of various RTV were studied using high precision electronic balance.The adhesive ability,surface resistance,and volume resistance of RTV influence by transformer oil were studied by changing experiment conditions,and the reasons for causing pollution flashover accident were analyzed by experimental data.The results indicate that,hydrophobicity transfer of RTV is affected by sample smudging method,the external insulating property of various RTV handling with oil immersion and artificial pre-pollution partly presents similarity.A relatively better ability to repulse oil is observed for RTV samples which are characterized by nano-SiO2 or fluorinated poly micro-powder,and the adhesion of various RTV samples by the impact of transformer oil is quite different.