【作者】 张文文；

【导师】 律方成；

【作者基本信息】 华北电力大学(北京) ， 工程硕士（专业学位）， 2022， 硕士

【摘要】 在导线、金具、均压环上包覆绝缘护套可以加强线路绝缘,能够有效减少鸟粪闪络、异物搭接等引起的线路故障。但是目前对绝缘护套的配置方法还缺少深入研究,并且绝缘护套在严寒地区使用时的性能研究较少。基于此,本文研究了包覆绝缘护套的架空输电线路放电特性,仿真分析了鸟粪对线路附近电场的影响,提出了绝缘护套的配置方法并验证了配置方法的有效性;人工模拟低温环境,研究了低温对护套材料的性能影响。搭建模拟鸟粪下落的试验平台,开展了包覆硅橡胶、氟硅橡胶绝缘护套的架空输电线路放电特性研究。试验获得了绝缘护套的电气特性与护套厚度、长度的关系,在此基础上,提出了适用于不同电压等级线路的绝缘护套配置方法。建立三维电场仿真模型进行仿真分析,结果表明:模拟鸟粪末端存在明显的电场畸变,是鸟粪下落导致线路闪络或跳闸的主要原因。开展了绝缘护套配置方法的有效性试验研究。根据真实鸟粪的特征配置模拟鸟粪液,利用模拟鸟粪喷射装置开展了鸟粪闪络模拟试验,获得了绝缘护套能够有效防止鸟粪闪络故障的概率。试验结果表明:用于110kV线路的硅橡胶绝缘护套与氟硅橡胶绝缘护套能够有效防止鸟粪闪络跳闸的概率分别为90.0%和93.3%;用于220kV线路的硅橡胶与氟硅橡胶绝缘护套能够有效防止鸟粪闪络跳闸的概率均为86.7%,表明本文提出的绝缘护套配置方法是可行有效的。研究了低温对硅橡胶和氟硅橡胶材料的性能影响。人工模拟-50℃环境,将两种材料放置在该环境中冷冻0～1050个小时,两种材料的耐击穿性能、力学性能随低温处理时间的增加均有显著变化,材料在室温下恢复0～15天后,两参数均小幅恢复;两种材料在冷冻状态下的硬度很高,在室温下可以迅速恢复;持续低温会导致试样表面出现深度极小的裂纹及孔洞,对试样的电气性能及机械性能影响不大。在试验研究过程中,氟硅橡胶材料所表现出的低温性能比硅橡胶材料更加优异稳定。更多还原

【Abstract】 Coating insulation sheaths on wires,fittings,and grading rings can strengthen the line insulation,which can effectively reduce line failures caused by bird droppings flashovers and foreign body splicing.However,there is still a lack of in-depth research on the configuration method of the insulation sheath at present,and there are few studies on the performance of the insulation sheath when it is used in severe cold areas.Based on this,this paper studies the discharge characteristics of transmission lines covered with insulation sheaths,simulates and analyzes the influence of bird droppings on the electric field near the lines,proposes a configuration method for the insulation sheath,and verifies the effectiveness of the configuration method;artificially simulates low temperature environment,studies the effect of low temperature on the properties of the sheath material.Build a test platform for simulating bird droppings,and conduct research on the discharge characteristics of transmission lines covered with silicone rubber and fluorosilicone rubber insulation sheaths,the relationship between the electrical properties of the insulation sheath and the thickness and length of the sheath is obtained through the test.On this basis,proposed the method of configuring the insulation sheath suitable for lines with different voltage levels.Established a three-dimensional electric field simulation model,and the results show that there is obvious electric field distortion at the end of the simulated bird droppings,which is the main reason for the line flashover or tripping caused by the falling of bird droppings.Carried out the effectiveness test research of the insulation sheath configuration method.According to the characteristics of real guano,simulated guano liquid was configured,and a simulated guano flashover test was carried out by using a simulated guano spray device,and the probability that the insulation sheath could effectively prevent the guano flashover failure was obtained.The test results show that the silicone rubber insulation sheath and fluorosilicone rubber insulation sheath used for 110kV line can prevent the probability of bird droppings flashover tripping by 90.0%and 93.3%respectively;The silicone rubber insulation sheath and fluorosilicone rubber insulation sheath used for 220kV line can effectively prevent the guano flashover tripping probability of 86.7%,indicating that the insulation sheath configuration method proposed in this paper is feasible and effective.Study the effect of low temperature on the properties of silicone rubber and fluorosilicone rubber materials.Artificial simulation of-50℃ environment,the two materials were placed in this environment for 0～1050 hours of freezing,the breakdown resistance and mechanics properties of the two materials were significantly improved with the increase of low temperature treatment time,and the materials recovered at room temperature after 0～15 days,both parameters decreased slightly;the hardness of the two materials was very high in the frozen state,and they could recover quickly at room temperature;the continuous low temperature would cause cracks and holes with extremely small depths on the surface of the sample,which has little effect on the electrical and mechanics properties of the sample.In the process of experimental research,the low temperature performance of fluorosilicone rubber material is more excellent and stable than silicone rubber material.更多还原