【作者】 练波；

【导师】 孙才新；

【作者基本信息】 重庆大学 ， 电气工程， 2002， 硕士

【摘要】 变压器作为电力系统的枢纽设备，其运行可靠性直接关系到电力系统的安全与稳定。本文针对应用油中溶解气体分析方法(Dissolved Gases Analysis，简称DGA)进行变压器绝缘监督时所遇到的主要技术难点，提出了提高变压器故障诊断的准确性、可靠性的几种模型和方法，主要研究内容如下： 基于电力变压器油中气体的产生和溶解原理，深入分析了油中溶解气体与变压器故障类型之间的关系，进而油中溶解气体的组分和含量可以作为变压器故障诊断的特征量；通过对判断变压器故障常用的三比值法和改良电协研法的深入分析，其诊断准确率较高，但对故障原因、故障现象和故障机理间同时存在不确定性和随机性的变压器等电气设备的故障诊断，难于满足工程应用的需要； 变压器由于结构的封闭性，给状态检测和故障诊断带来一定的困难，但一台运行中的变压器既不是状态特征信息十分明确的白色系统，也不是状态特征信息一无所知的黑色系统，可以视为一个典型的灰色系统；本文将灰色关联理论引入到变压器内绝缘故障诊断中，通过分析变压器发生绝缘故障时的原因与油中溶解特征气体含量的关系，采用均值生成统计方法，提出了诊断变压器故障的标准模式特征向量矩阵； 深入分析了灰色关联度的分辨系数的特性，针对常用灰色关联度的不足性，基于几何空间理论，提出了一新的灰色关联度计算公式，并证明了满足灰关联度四公理，以及按此关联度确定关联序的准则，该方法充分利用了各点关联系数提供的丰富信息，在一定程度上弥补了邓氏关联度存在的局部关联倾向及信息损失的固有缺陷，其数学意义和物理意义明显； 在Windows98平台下，使用Visual Basic编程语言形成一个独立的软件包；经过大量的诊断实例表明：本文的灰色关联分析诊断方法对电力变压器绝缘故障诊断是有效的，它能够分析出变压器的绝缘状况，正确识别绝缘故障类型并能给出故障发生的大致部位，诊断的准确性大大高于常用的三比值法。更多还原

【Abstract】 The operation reliability of the power transformer,which is the major equipment in power system,directly related to the safety and stability of whole power system. In accordance with the technological difficulties encountered in the process of insulation supervision based on the Dissolved Gases Analysis (DGA),several kinds of model and method are presented to improve the reliability and precision of fault diagnosis of the power transformer. Main research content includes:Starting from the study of occurring and resolving theory for gases in transformer oil,the relationships between oil-dissolve gases and the transformer fault types are further analyzed,all of which contribute to the final conclusion that the contents and constituents of oil-dissolved gas can be considered as the character parameter for diagnosing transformer faults.By deeply studying the common transformer faults diagnosing methods,such as three-ratio methods and improved electrical committee agreements,several shortcomings such as uncertainness judgment when the fault reasons,phenomenon and principles come out together while can not consistent to each other etc. For this reason,the old methods can not fully meet need to engineering practical application.The enclosure structure of power transformer leads to difficulties in condition monitoring and fault diagnosis. However,if considering from another angle,the working power transformer,which is neither a white system with definite status information,nor a black system without any information about status information,can be defined as typical gray system.In this paper,the gray relationship theory is introduced into transformer insulation diagnosis. Based on analyzing the relationship between the reasons of transformer insulation faults and contents of each gases dissolved in transformer oil,the standard mode character parameters matrix is presented.The character of distinguishing coefficient is analyzed. For the purpose of overcoming the disadvantages of general gray relationship degree theory,a creative gray relationship degree calculation formula ground on spatial geometry theory. In addition,4 satisfaction axioms is proved,by which the relationship order can be confirmed. By this method,abundant information binding behind every relationship coefficient can be fully utilized,which will make up the limitation of Deng relationship degree to some extend. The mathematics and physics meaning is prominence.Developed by Visual Basic,A software package is built in the environment of windows98. Plenty of diagnosis examples demonstrate the validity of the gray relationship analysis method in diagnosing power system insulation faults. The transformer insulation condition can be analyzed,as well as the fault position can be located by recognizing the fault types. The diagnosing precision is much higher than former three-ratio method.更多还原