较低湿度下含糖污秽绝缘子放电特性

发布时间：2018-11-07 08:10

【摘要】：部分地区外绝缘表面污秽含有大量有机物,影响绝缘性能。本文通过化学分析、模拟试验、污闪试验及分子动力学与量子化学计算,研究了较低湿度下葡萄糖污秽对绝缘子放电的影响,弄清了某变电站在较低湿度下由葡萄糖污秽引起的外绝缘大面积放电的特性。结果表明:由于葡萄糖吸湿性强,当污秽物中葡萄糖含量超过0.10mg/cm~2时,污层泄漏电流远大于常规污秽。电流热效应使含葡萄糖污秽的绝缘子表面电位分布更不均匀,显著降低污秽绝缘子起始放电电压;同时葡萄糖具备较活泼化学性质,在强电场中或强烈放电时,电能使葡萄糖断键,生成带电荷的自由基,加快绝缘子表面的电子转移速率,增加放电强度。葡萄糖的物理和化学特性是造成较低湿度下外绝缘沿面放电现象的原因。
[Abstract]:Some areas of external insulation surface contamination contains a large number of organic matter, affecting insulation performance. In this paper, the effects of glucose contamination on insulator discharge at low humidity are studied by chemical analysis, simulation test, pollution flashover test, molecular dynamics and quantum chemistry calculation. The characteristics of large area discharge of external insulation caused by glucose contamination at low humidity in a substation are clarified. The results show that the leakage current of the polluted layer is much higher than that of the conventional contamination when the glucose content in the polluted material exceeds 0.10 mg / cm ~ 2 because of its strong hygroscopicity. The surface potential distribution of the insulator containing glucose contamination is more uneven due to the current thermal effect, and the initial discharge voltage of the contaminated insulator is significantly reduced. At the same time, glucose has more active chemical properties. In the strong electric field or intense discharge, the electric energy breaks the bond of glucose, generates the charged free radical, accelerates the electron transfer rate on the surface of insulator, and increases the discharge intensity. The physical and chemical properties of glucose are the reasons for the discharge of external insulation at low humidity.
【作者单位】：广东电网有限责任公司电力科学研究院;武汉大学电气工程学院;
【分类号】：TM216

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