运行直流复合绝缘子的憎水性分布规律

Hydrophobicity Distribution of DC Composite Insulators in Service

憎水性是衡量复合绝缘子运行性能的重要指标,研究憎水性分布规律有助于对测试结果进行更准确的评价。为此,以4支实际运行后的直流复合绝缘子为研究对象,分别采用喷水分级法和静态接触角法,进行了自然污秽下和去除污秽后的憎水性测试以及人工涂污后的憎水迁移性测试。研究结果表明,绝缘子高压端和低压端的憎水性整体差于中部,沿串表现出倒U形的憎水性分布,同时憎水迁移性较差的伞裙也更多出现在高压端和低压端附近;同片伞裙中边沿位置褪色较为严重,相比于褪色较轻的伞裙根部,其去除自然污秽后的憎水性较好,但是人工涂污下憎水迁移性明显较差。在各种憎水性试验中选择适合的测试方法,根据以上憎水性分布规律合理选取憎水性测试位置,所得试验结果能更好表征复合绝缘子运行性能。

Hydrophobicity is an important indicator for the operating performance of composite insulators and insights to hydrophobicity distribution help to provide an accurate evaluation on test results.Thus,four DC composite insulators energized over a period of years were selected to conduct hydrophobicity tests with hydrophobicity classification method and static contact angle method.These tests included the hydrophobicity measurement with and without natural contamination and the hydrophobicity transfer with artificial contamination.Experimental results indicate that the high-voltage end and low-voltage end show obviously worse hydrophobicity and hydrophobicity transfer than the middle part.In other words,the hydrophobicity and hydrophobicity transfer along the insulators are mostly inverted U-shaped.Moreover,the edges of sheds with obvious fading phenomenon show better hydrophobicity when the natural contamination is removed,but the hydrophobicity transfer is much worse than the roots.According to the hydrophobicity distribution above mentioned,the results of hydrophobicity tests can better characterize the operating performance of composite insulators by properly choosing experimental methods and test position.