【作者】 张立学；

【导师】 陈继明；

【作者基本信息】 中国石油大学 ， 控制工程， 2010， 硕士

【摘要】 目前复合绝缘子已广泛应用于世界上许多地区。美国新生产的绝缘子有60%-70%为复合绝缘子,中国也有几百万只复合绝缘子在35kV-500kV交流输电线上运行并主要被应用于污秽地区。复合绝缘子的主要优点有:安装容易、重量轻、防污性能好、维护费用低、机械强度高等。由于复合绝缘子外绝缘使用的是有机复合材料,故老化是主要的问题。如何检测线路上绝缘子老化后的质量情况,对于电网的安全运行具有十分重要的意义。由于供电部门一般并不具备完善的绝缘子检测条件(如污秽闪络试验等),为此本文探索了检验复合绝缘子质量的简单易行的方法。首先,本文通过对比新复合绝缘子和从线路上拆下的相同型号的复合绝缘子的闪络特性及机械特性,说明了运行一段时间后这些特性的变化情况。这些信息对于35kV绝缘子的应用具有参考意义。轻微老化对绝缘子的工频干闪、冲击闪络电压影响不大。绝缘子泄漏电流的幅值和波形可以提供复合绝缘子质量评估的重要信息,故可通过测量泄漏电流评估其老化情况。绝缘电阻的测量对于评估表面憎水性也有一定的作用。测漏电流与绝缘电阻的变化是由于复合绝缘子受到物理化学腐蚀后,表面微观结构发生变化造成的,而微观结构的变化可以利用扫描电镜来观察。扫描电镜是分析表面粗糙度的很好的方法。憎水性是复合绝缘子优异于瓷绝缘子的独特性能,因此如何评估憎水性的好坏十分重要。接触角测量以及HC分级都是比较简单易行的方法,接触角测量时,其测量结果与水滴的大小以及在材料表面上停留的时间有较大关系。HC分级比较简单,但对于绝缘子整体性能评估仍有缺陷。本文通过试验,分析了复合绝缘子憎水性与其湿闪电压的关系。更多还原

【Abstract】 Recently, composite insulators are increasingly used in power systems around the world. Now 60-70 percent of the newly produced insulators in the United States are composite insulators. In China, there are millions of composite insulators installed in 35kV-500kV power networks which are mostly used in the polluted areas. Composite insulators are easy to manufacture and are very light. The mechanical strength of composite insulators is also very high.Aging is a serious problem because composite insulators are made of organic materials. How to estimate the quality of the composite insulators is valuable to power network safety. As most power supply bureaus cannot carry out the pollution flash over test, this paper explores easy methods to detect the quality of composite insulators through experiment.Test on insulators having been in service for 3-5 years shows their good performance. This result may serve dance for other 35kV insulators. Little aging has less influence on the dry flashover and impulse flashover voltage of composite insulators. It is proposed to measure the magnitude and shape of leakage current as they can provide important information of composite insulator quality. The increase of leakage current and surface resistance is caused by the change of microcosmic state of the surface of composite insulators, which can be detected by scanning electron microscope (SEM). Hydrophobicity is the proper characteristic of composite insulators which can be evaluated by contact angle and insulating resistance measurement and it can be classified by HC classification. The contact angle measuring result is related to the volume of water drop. HC classification is very simple, but the result is not sufficient for evaluating the whole insulator. The relationship of hydrophobicity and wet flashover voltage of composite insulators is also discussed in this paper.更多还原