基于介电响应的油纸绝缘寿命预测方法

Method for predicting lifetime of oil-paper insulationbased on dielectric response

油纸绝缘是油浸式电力变压器的重要组成部分,其绝缘寿命受热老化因素影响很大。因此,针对不同温度、不同含水率下的油浸纸板的寿命预测问题进行分析,提出一种应用平移因子和纤维素反应二阶动力学方程预测不同温度、不同含水率下的油浸纸板寿命的方法。首先,针对不同含水率的油浸纸板进行变温介电谱测试和130℃条件下的加速老化试验;其次,依据频温叠加的基本原理,将所测的介电损耗曲线进行计算平移,得到相应含水率油浸纸板的平移因子,根据平移因子计算相应油浸纸板的活化能,并得出油浸纸板含水率与活化能的关系式,重新构造平移因子表达式;最后,将130℃下测得的老化试验数据和平移因子代入纤维素反应二阶动力学方程,使得该模型可以计算不同温度、不同含水率下的油纸绝缘老化寿命。

Oil paper insulation is an important part of the oil immersed power transformer,and its insulation life is mainly affected by thermal aging.Therefore,this paper analyzes the life prediction of oil-impregnated pressboard under different temperatures and moisture contents,and proposes a method to predict the life of oil impregnated paperboard under different temperatures and moisture contents by using translation factor and cellulose reaction second-order kinetic equation.Firstly,oil-impregnated pressboard with different moisture content to variable temperature dielectric spectrum test and 130℃under the condition of accelerated aging test were carried out.Secondly,according to the basic idea of frequency temperature superposition,the measured dielectric loss curve was calculated for translation,then the translation factor of oil-impregnated pressboard was obtained.According to the translation factor,the activation energy of the corresponding oil-impregnated pressboard was calculated and the algebraic relationship was established between moisture content and activation energy of oil-impregnated pressboard,reconstructing the translation factor expression.Finally,with aging test data being measured under 130℃and translation factor into two order kinetic equation of cellulose reaction,this model can be used to predict the aging life of oil paper insulation under different temperatures and moisture content.