【作者】 田小强；

【导师】 李琦；

【作者基本信息】 西安理工大学 ， 电气工程， 2003， 硕士

【摘要】 本文主要研究了变电污秽在线监测和模糊报警模型两个问题。 介绍了变电污秽及其相关概念，并对国内外现有的变电污秽防治方法和变电污秽在线监测方法进行了研究。文中比较了各种传统的变电污秽防治和监测方法，指出了各自存在的不足。 分析了泄漏电流的产生机理和特点，并在此基础上研制了一种精度高、频带宽的泄漏电流传感器。简单介绍了变电污秽在线监测系统的设计。认真研究了污秽泄漏电流与环境温度、湿度和污秽程度之间的关系，指出了以往采用恒值报警模型存在的问题。提出要提高报警的可靠性必须利用泄漏电流、温度、湿度与绝缘子污秽程度的非线性关系，进行非线性报警。由于无法得到泄漏电流、温度、湿度与绝缘子污秽程度之间的非线性关系，因此，本文设计了一种基于模糊推理的非线性报警模型的方法。并利用Visual Basic语言编制了模糊报警程序，并将其应用于实际系统。 理论分析和实际运行的结果表明本文的变电污秽在线监测系统能够适应泄 西安理工大学工程硕士专业学位论文露屯流人范围的变化，及时并准确地预报绝缘于污秽程度，为解汰了变屯污秽分线监测系统的可靠报警问题提供了新途径。更多还原

【Abstract】 The contamination on-line detecting method and fuzzy reasoning alarming model are discussed in this paper.Some basic concepts of insulator contamination are introduced firstly. Existing methods of avoiding contamination flashover and methods of detecting contamination degree of insulators are discussed in details. These methods are analyzed and disadvantages of them are pointed out.The arising mechanism and character of leakage current are analyzed. Based on these analyses, a high precise and wide bandwidth sensor is developed. The design of contamination on-line detecting system is introduced. The relationships between leakage current, environment humidity, environment temperature and level of pollution are studied, then, the problem of fixed value alarming model is analyzed. It is proposed that in order to increase the reliability of prediction, the nonlinear prediction model, which depends on the nonlinear relationships between above factors, is indispensable. Because the nonlinear relationships can hardly be obtained, a nonlinear alarming model based on fuzzy reasoning methodis developed in this paper. The fuzzy reasoning alarming has been realized by Visual Basic programming and used in practical systems.The results of theoretical analyzing and practical running proved that the contamination on-line detecting system for substation developed in this paper can be applied to the large-scale variation of leakage current, the fuzzy reasoning alarming method can predict the pollution level of insulator more accurately. A new method is given to solve the problem of alarming reliability of contamination on-line detecting system.更多还原