基于频域介电谱的环氧树脂浸渍皱纹纸绝缘受潮状态评估

Moisture condition evaluation of epoxy resin impregnated crepe paper based on frequency domain spectroscopy

环氧树脂浸渍皱纹纸(ERICP)绝缘材料被广泛应用于电力设备绝缘,受潮是影响其绝缘状态的重要原因。本文将频域介电谱(FDS)技术用于材料绝缘状态的评估,首先制备不同含水量的ERICP样片并开展FDS测试;然后根据FDS频谱曲线,分析FDS特征参数随含水量的变化规律;最后引入介电模量谱和模量因子,提出ERICP绝缘状态评估方法。结果表明:含水量的变化影响FDS曲线整体变化规律;介电模量能够有效抑制直流电导的影响从而表征内部弛豫过程;ERICP样片的介电模量谱在低频范围内出现了明显的弛豫峰,弛豫峰的特征频率随含水量的增加而升高;介电模量虚部的积分面积可以作为表征ERICP绝缘的特征参量,模量因子与含水量的关系同指数函数具有0.9975的拟合优度。

Epoxy resin impregnated crepe paper(ERICP)insulating materials are widely used in power equipment insulation,and moisture is an important reason affecting their insulation state.In this paper,the frequency domain spectroscopy(FDS)technology was used for insulation condition evaluation.Firstly,ERICP samples with different moisture content were prepared and carried out FDS tests.Then,according to the FDS spectrum curves,the variation law of FDS characteristic parameters with moisture content was analyzed.Finally,the dielectric modulus spectrum and modulus factor were introduced,and the insulation condition evaluation method of ERICP was proposed.The results show that the change of moisture content affects the overall change law of FDS curves.The dielectric modulus can effectively suppress the influence of DC conductivity to characterize the internal relaxation process.The dielectric modulus spectrum of ERICP samples has obvious relaxation peak in the low-frequency range,and the characteristic frequency of relaxation peak increases with the increase of moisture content.The integral area of the imaginary part of dielectric modulus can be used as a characteristic parameter to characterize the insulation condition of ERICP.The relationship between the modulus factor and moisture content has 0.9975 of goodness of fit with the exponential function.