基于回复电压方法诊断变压器油纸绝缘状态的关键技术研究

项目名称： 基于回复电压方法诊断变压器油纸绝缘状态的关键技术研究

项目编号： No.51307097

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 电工技术

项目作者： 张涛

作者单位： 三峡大学

项目金额： 25万元

中文摘要： 回复电压方法是一种诊断大型电力变压器的油纸绝缘状态的无损电气诊断方法，它能现场评估变压器固体绝缘的状态。现有研究主要利用主时间常数特征量，但缺乏准确界定主时间常数的方法，而且该特征量难以区分变压器固体绝缘的老化和受潮，这影响了该方法诊断的准确性。基于此，本课题深入研究该方法存在的若干关键问题：揭示变压器固体绝缘的受潮和老化对其介质响应特性及回复电压特征量的影响机理，明确不同绝缘缺陷引起相应特征量的变化规律；利用等值电路模型模拟其极化特性，建立分析绝缘老化状态的物理数学模型，应用改进的智能优化算法，辨识等值电路参数；计算新的特征量和极化谱，仿真极化谱的变化规律，提出确定主时间常数的新方法；建立利用主时间常数、初始斜率等多个介质响应特征量区分变压器固体绝缘老化和受潮的综合评估模型，并提出诊断方法，提高诊断的可靠性。本项目的研究成果将完善回复电压诊断方法的基础理论，为工程应用提供理论基础。

中文关键词： 回复电压；油纸绝缘；变压器；绝缘诊断；介电特性

英文摘要： Return voltage method is a non-destructive electrical diagnosis technique for assessing of oil-paper insulation condition of large-scale power transformer. According to the existing research and application, dominant time constant is the most commonly used characteristic quantity, but it is difficult to define dominant time constant accurately. Moreover，it is difficult to separate ageing and moisture on solid insulation.The study is not deep on correlation between initial slope and insulation condition, which has influenced the accuracy of result obtained by the method. On the basis of the fact, this project studies the several key issues of the method. Firstly we will investigate on the polarization mechanism of oil-paper insulation system, revealing the correlation between polarization spectrum, initial slope and insulation condition were experimentally studied, making clear the change law of corresponding characteristic quantity with various insulation defects,such as ageing and moisture.simulate its polarization properties using equivalent circuit model, then establishe a mathematical-physical model for analysing insulation conditions; adopt the improved intelligence optimization algorithm to identify equivalent circuit parameters of dielectric response accurately. Secondly, characteristic quantity and polar

英文关键词： return voltage；oil-paper insulation；transformer；insulation diagnosis；dielectric characteristics