线路绝缘子非均匀染污方法及污闪特性

目前人工污秽试验中绝缘子染污采用均匀涂抹，而自然污秽受风力、雨水、绝缘子形状、污秽粒径等因素影响，在绝缘子表面非均匀累积，非均匀积污对绝缘子U_50%产生影响，通过对多地区、大范围绝缘子自然积污特性研究，获得不同伞形绝缘子上下表面积污特性的差异性规律，提出了基于绝缘子自然积污规律的上下表面非均匀染污方法，开展了交/直流电压下绝缘子非均匀染污人工污秽试验，获得了非均匀染污下污闪特性曲线，采用绝缘子上下表面非均匀染污方法对绝缘子进行染污更接近绝缘子实际运行工况，人工污秽试验结果更准确合理。试验结果表明：上下表面染污非均匀度越大，U_50%值越大；随着染污非均匀度增大，U_50%增大幅度减小，逐渐趋于饱和。主要结论对绝缘子串长优化及选型具有重要参考意义。

Non-uniform Pollution Method and Pollution Flashover Characteristics of Transmission Line Insulators

At present, pollution of insulators in artificial contamination test is done by uniform smearing, but natural pollution, affected by wind, raining, insulator shape, pollution, pollutant particle size and other factors, is a non-uniform accumulation on the insulator surface, and the non-uniform contamination has an effect on the insulator U_50%. Based on a study of the natural pollution characteristics of insulators in multiple regions of a large area, different pollution characteristics of the upper and lower surfaces of different umbrella insulators are obtained, and a non-uniform artificial pollution method is proposed for the upper and lower surfaces of insulators based on the natural contamination characteristics. Non-uniform artificial contamination tests were carried out for the insulators under AC/ DC voltage, and the corresponding pollution flashover curves were obtained. The test results show that the contamination of the insulators by non-uniform pollution method is close to the actual operating conditions of insulators, and the testing results are more accurate and reasonable. It is concluded that the more non-uniform of the contamination on the upper and lower surfaces, the larger the U_50% value is, but the incremental amplitude of U_50% decreases and tends to be saturated. The main conclusions of this paper are of great significance for the optimization of insulator string length and type selection.