高压复合支柱绝缘子外绝缘特性及防冰伞应用

External Insulation Characteristics and Anti-ice Umbrella Application of HV Composite Post Insulators

复合支柱绝缘子伞裙为硅橡胶材料,由于其优异的绝缘性能,越来越多的应用于变电站及换流站内,而现有的复合支柱绝缘子的设计依托原有瓷支柱的试验结果,不具备经济性,需要开展复合支柱绝缘子的外绝缘特性研究,优化特高压站用复合支柱绝缘子伞形结构设计,提升外绝缘特性,降低工程造价。为此开展了4种伞形结构的复合支柱绝缘子人工污秽、覆冰、淋雨试验,并与瓷支柱的试验结果进行了对比。结果表明,复合支柱绝缘子在亲水性下的沿爬电距离的污闪电压梯度与瓷支柱的试验结果无明显差异,而在弱憎水性和憎水性完全恢复下的复合支柱绝缘子较瓷支柱分别提高24.3%~29.8%和58.9%~65.6%;在满足爬电距离要求的基础上,大小伞和一大两小伞均可作为推荐伞形。由于复合支柱绝缘子覆冰闪络电压较污秽、淋雨闪络电压低,设计了一种添加防冰伞裙的特高压复合支柱绝缘子,并开展了特高压支柱绝缘子原件及防冰伞试品人工污秽、覆冰试验,获得了特高压复合支柱绝缘子人工污秽闪络特性、覆冰闪络特性,优化后的特高压复合支柱绝缘子沿爬电距离的冰闪电压梯度可提高27.1%。

Composite post insulator sheds are made of silicone rubber.Possessing excellent insulation properties,the composite post insulator sheds are more and more used in substations and converter stations.The design of existing composite pillars relies on the experimental results of the original porcelain pillars,and it is not economical.So it is necessary to research the external insulation properties of composite pillars,to optimize the design of composite pillar umbrella structures for UHV stations,to improve external insulation properties,and to reduce project cost.Consequently,we carried out experiments of artificial contamination,ice coating,and rain tests of four kinds of umbrella-shaped composite post insulators,and compared them with the experimental results of porcelain pillars.The results show that no significant differences exist in the flash voltage gradient along the creepage distance between the composite pillar and the ceramic pillar under the hydrophilicity test results.Compared with the porcelain pillars,the properties of the composite pillars with full recovery of weak hydrophobic and hydrophobic properties will be increased by 24.3%~29.8%and 58.9%~65.6%.When the requirements of creepage distance are satisfied,the umbrellas of one big and one small umbrellas/one big and two small umbrellas are recommended.For the ice-covered flashover voltage of composite pillar is lower than that of the pollution and rain,the UHV composite post insulator with an anti-ice umbrella skirt is designed,and contamination and ice tests are carried out.Thereby,the artificial pollution flashover characteristics and the ice-flashing characteristics of the UHV composite pillar original and optimized umbrella shape are obtained,and the ice-flashover voltage of optimized UHV composite post insulator can be increased by 27.1%.