采用微分去极化电流法解析变压器油纸绝缘的介质响应函数

Dielectric Response Function for Transformer Oil-paper Insulation Solved by the Method of Differential Depolarization Current

时域介质响应诊断技术是有效诊断变压器油纸绝缘状态的无损检测方法,而绝缘的介质响应数学模型是时域诊断研究的关键手段。针对原有模型未能准确反映介质的极化过程,现有建模方法无法确定极化过程包含的弛豫项数、未能准确地辨识模型参数等问题,根据电介质物理学的研究成果,将方根指数型衰减规律引入介质响应函数,以便其更贴近多种不同条件下的实验规律。同时,在建模中提出了微分去极化电流法,从而解决了一直以来受争议的弛豫项数问题,并实现了介质响应函数的解析。研究结果证明了利用微分去极化电流法建模的唯一性和准确性,为油纸绝缘的时域介质响应诊断提供了新思路。

The time domain dielectric response diagnosis technology is an effective nondestructive testing method for diagnosing transformer oil-paper insulation states.The dielectric response mathematical model of insulation is a crucial means of the time domain diagnosis.To accurately reflect the medium depolarization process,to determine the number of the relaxation which depolarization process contains,and to accurately identify the parameters for the model,according to the research results of dielectric physics,the radical exponential decay law was introduced into dielectric response function in order to make the function closer to the experimental rule in a variety of different conditions.At the same time,a differential depolarization current method is put forward in the modeling,solving a controversial problem of the number of relaxation,and realizing the solving of dielectric response function.The results show that the differential depolarization current method is accurate,providing a new idea for the time domain dielectric response diagnosis of insulation medium.