应用极化/去极化电量差模型分析油纸绝缘微水扩散暂态过程

Analysis of Transient Moisture Diffusion in Oil-paper Insulation Using Polarization and Depolarization Charge Difference Model

为使用极化/去极化电量差法分析油纸绝缘微水扩散暂态过程,建立了时域极化/去极化电量差模型,用极化/去极化电量差法分析了不同绝缘纸厚度不同微水质量分数时油纸绝缘的极化/去极化特性,利用时域极化/去极化电量差模型仿真分析了微水扩散暂态过程中油纸绝缘的极化/去极化电量差变化特征。分析结果表明:电量差法能够很好地反映油纸绝缘中微水质量分数的变化,时域极化/去极化电量差模型能够有效反映油纸绝缘微水扩散暂态变化过程。绝缘纸厚度对油纸绝缘极化/去极化电流曲线的影响程度随着绝缘纸厚度的降低而减小。随着油纸绝缘中微水质量分数的增加,电量差与测量时间之间的线性关系更加显著,直线的斜率也随之增加。随着扩散时间的增加,同一测量时刻油纸绝缘极化/去极化电量差沿油纸厚度方向上逐渐趋于等量分布,极化/去极化电量差与测量时间的线性关系更为显著,直线斜率逐渐增大。

In order to apply the polarization and depolarization charge difference method to analyses of transient moisture diffusion in oil-paper insulation, we put forward a time-domain polarization and depolarization charge difference model. We used the method to analysis the polarization and depolarization characteristics of oil-paper insulation with different thickness and moisture content, and then used the model to analysis the charge difference of oil-paper insulation in the process of transient moisture diffusion. It is obtained that the charge difference method reflects moisture content in oil-paper insulation effectively while the proposed model reflects the process of transient moisture diffusion effectively. As the thickness decreases, its influence on the curves of polarization and depolarization current of oil-paper also decreases. As moisture content in oil-paper insulation increases, the linear relationship between charge difference and measurement time gets more significant with an increasing slope. As diffusion time increases, polarization and depolarization charge difference gradually becomes equally distributed along the oil-paper thickness direction at the same moment. The linear relationship between charge difference and measurement time is more significant with an increasing slope.