输电线路覆冰问题威胁着电力系统的安全运行。由于缺乏有效的防覆冰手段,覆冰事故时有发生。鉴于此,介绍了清华大学在人工覆冰试验方法的自然等效性和绝缘子防覆冰涂料方面的相关研究工作。现有人工气候室试验方法和相关标准主要采用覆冰厚度和形态等参数去模拟自然覆冰形态,该研究则采用从覆冰速度上模拟自然覆冰环境的方法,通过选择覆冰水滴大小和环境温度的配合,模拟危害较大的湿增长覆冰过程,并使覆冰速度接近自然覆冰环境。防覆冰涂料研究方面,采用一种结合了憎水性和表面发热特性的半导电材料,通过试验验证了憎水性叠加发热性的表面对覆冰过程的影响;并在3片绝缘子短串上,得到了有效防冰所需的泄漏电流值。试验结果表明该种防冰涂料可有效防止绝缘子串表面的覆冰形成。
Ice accumulation on insulators and transmission lines imposes serious problems on power systems,and serious incidents happen occasionally due to the lack of effective countermeasures.We introduced the recently progress of the work by Laboratory of Advanced Technology of Electrical Engineering Energy at Tsinghua University on the artificial icing test methods and anti-icing material for insulators.Unlike the commonly used icing methods which focused on making the ice weight and shape similar to the natural icing,we proposed a methods to make the icing speed as close as the wet-growth in natural conditions by choosing the size of the water droplets and the ambient temperature.A semiconducting coating was investigated,and the surface heating effect and anti-icing performance were tested.The anti-icing performances of these RTV silicone rubber coatings on short insulators strings of three pieces insulators with different leakage current magnitudes were compared in a climate chamber,and the sufficient leakage current for anti-icing was derived from the experiments.The results show that the surface heating effect,together with the hydrophobicity,can significantly reduce the formation of ice on insulators.