【作者】 杨洋；

【导师】 孙才新；

【作者基本信息】 重庆大学 ， 电气工程， 2010， 硕士

【摘要】 在输变电系统中,输电线路的覆冰现象十分普遍。覆冰可以引起导线舞动、断线、倒塔,导致绝缘子外绝缘特性的严重下降并引起绝缘子闪络,给电网安全运行造成了严重损害。虽然目前在电力系统中广泛运用的包括RTV涂料在内的憎水性涂料具有良好的憎水性,但其接触角不会超过110o,故并不能起到防覆冰的效果,更不能提高绝缘子串冰闪电压以及和阻止冰闪事故的发生,到目前为止,尚未见应用的实际效果。为有效地减少覆冰事故的发生,有必要研究仿荷叶超疏水涂层,这种涂层成膜后水珠在其上面的接触角可达到150o以上,滚动角小于5o,使得水珠在上面很容易滚动和滑落。将这种涂层涂敷在输变电线路的绝缘子上,其超疏水性能能够使滴落于绝缘子上的过冷却水滴在释放潜热前就已经滚走,从而有效降低绝缘子表面对过冷却水滴的捕获率,进而延缓和阻止覆冰事故的发生。本文基于“荷叶效应”,研究了一种超疏水涂层的制备方法及其疏水性能表征。并将涂敷有此种超疏水涂层的等腰三角形玻璃板、涂敷RTV涂层的等腰三角形玻璃板与没有涂层的等腰三角形玻璃板一起放入人工覆冰实验室进行覆冰实验,并对这三种试品的覆冰形貌、覆冰重量、耐压过程中的紫外光子数和泄漏电流以及覆冰结束后的交流冰闪电压进行测试、比较和分析。为考察超疏水涂层运用于绝缘子防覆冰的效果,将涂敷有此种超疏水涂层的三片玻璃绝缘子、涂敷RTV涂层的三片玻璃绝缘子与没有涂层的三片玻璃绝缘子一起放入人工覆冰实验室进行覆冰实验,并基于试验结果,提出了改进涂料配方以及配合超疏水涂料的防冰除冰措施的研究思路。通过大量的试验及其结果分析得到以下结论:①超疏水涂层表面具有微纳二元复合粗糙结构,从而形成了“荷叶效应”和超疏水状态,静态接触角可以达到(160±0.5)o,这种表面水与固体的接触分数为6.6%,也就是说存在93.4%的空气截留面积;②超疏水涂层能明显延缓等腰三角形玻璃板以及绝缘子试品的覆冰,阻止了连续覆冰膜的产生,在覆冰过程中表面只有分离的覆冰颗粒,由于超疏水涂层具有较低的滚动角,涂覆超疏水涂层的等腰三角形玻璃板试品在覆冰过程中倾斜的角度越大,覆冰量越小,延缓覆冰的效果越明显;③由于超疏水涂层阻止了连续覆冰膜的产生,表面只有分离的覆冰颗粒,所以在耐压过程中涂覆超疏水涂层的玻璃板试品的泄漏电流远远没有涂覆RTV涂层的试品和没有任何涂层的试品强,且用紫外成像仪测得的耐压紫外光子数远远低于涂覆RTV涂层的试品和没有任何涂层的试品;④测得的涂覆超疏水涂层的等腰三角形玻璃板以及绝缘子试品的交流冰闪电压远远高于涂覆RTV涂层的试品以及没有任何涂层的试品的测量值;⑤改善超疏水涂料的配方工艺,例如采用复合纳米粒子代替单一粒径的无机纳米粒子,以实现规整的双重粗糙结构以及持久的超疏水性,并探讨超疏水涂料与其它防冰除冰措施相配合方法,如在超疏水涂料中添加电热型材料、光热型材料以及PTC材料,以增加超疏水涂膜对连续覆冰膜形成的有效阻止时间,对于电力系统输配电装备防覆冰事故和系统安全有着一定的研究意义。更多还原

【Abstract】 In the power transmission system,icing is widespread phenomenon,which can cause bounce and rupture of transmission line and even lead to the fall of iron tower.With icing,the external insulation characteristics are always deteriorated to the extent that the flashovers of insulators can easily occur,which means the safety and stability of power transmission system are strongly chanllenged by icing.Notwithstanding the fact that super-hydrophobic coatings like RTV are widely used in power transmission system,they,with their contact angler not bigger than 110o,can’t prevent icing at all,therefore the AC flashover voltage of insulators can’t be increased when icing occurs.In order to prevent icing accendents and to decrease flashovers in icing,it is necessary to study and develop super-hydrophobic coating,on which the contact angle of water is bigger than 150o so that the waterdrops easily roll and fall from the surface of coating.On the surface of insulators painted with superhydrophobic coating,the water rolls and falls,which means that the waterdrops are scarecely captured,so icing can hardly happen.From this point of view,super-dydrophobic coating is a good method to prevent icing accidents and AC flashover of insultors.Based on lotus effect,the technics of preparing the super-hydrophobic coating is studied and its hydrophobicity properties analyzed.One glass-plate with this super-hydrophobic coating,one with RTV coating,and one without any coating are put together in the artificial climate chamber for icing test.Their surface ice morphology,their icing weight,their leakage current’s frequency spectrum and their AC flashover voltage are tested,compared and studied.In order to know the anti-icing effects of this super-hydrophobic coating when used for isulators,3 insulators with this super-hydrophobic coating,3 with RTV coating and 3 without any coating are put in artificial climate chamber for icing test and based on the test results,the methods of developing the superhydrophobic coating and the auxiliary methods which can make anti-icing of this super-hydrophobic coating more effective are studied.The following conclusions are made based on test results:1) Micro-nano roughness structure is found on the super-hydrophobic coating,which leads to lotus effect and super-hydrophobicity.Only 6.6% of this surface is in contact with waterdrop on it and 93.4% with air; 2) The super-hydrophobic coating can evidently delay the icing process on glass-plate samples and insulators,and due to its super-hydrophobicity,the larger the inclination angle of the glass-plate sample with super-hydrophobic coating is,the less the weight of ice on it;3) Because the super-hydrophobic coating inhibits the forming of continuous ice film and on the surface of super-hydrophobic coating are only separated ice particles,the leaking current of the glass-plate sample with super-hydrophobic coating is much smaller than that of glass-plate sample with RTV coating and without any coating and the number of photons of the sample with super-hydrophobic coating discovered by ultraviolet imaging spectrograph is much less than that of sample with RTV coating and without coating;4) It is found that the flashover voltage of the sample with super-hydrophobic coating after icing is much higher thant that of the sample with RTV coating and without coating;5) It is very important for the safety of power transmission system to increase the inhibition time of super-hydrophobic coating against icing by replacing nano-particles of the same size with composite particles in making the coating or by developing auxiliary anti-icing measures.更多还原