基于Havriliak–Negami介电弛豫模型的油纸绝缘状态评估

Status Assessment of Oil-paper Insulation Based on Havriliak Negami Dielectric Relaxation Model

为了定量分析水分质量分数、温度及绝缘纸聚合度对油纸绝缘频域介电谱的影响，将HN介电弛豫模型用于研究油纸绝缘频域介电谱特性。采用复分析理论和几何方法得到了HN介电弛豫模型实部、虚部与其模型参数的解析式。分别测试了5组不同水分质量分数、温度及聚合度油纸绝缘试样的频域介电谱，采用HN介电弛豫模型对介电频谱进行了计算拟合，并分析了水分质量分数、温度及聚合度对HN介电弛豫模型参数的影响。结果表明：弛豫时间常数与水分质量分数、温度、聚合度分别满足对数线性关系、Arrhenius方程及线性关系；高频介电常数及其与静态介电常数之差随着水分质量分数、温度、聚合度的增加而增大；形状参数∥随着水分质量分数、温度的增加而增大，随着聚合度增大而下降；形状参数a的值均落于0．7～0．9之间。

To quantitatively analyze the influences of changes of moisture content, temperature, and degree of polymeri- zation （DP） on the frequency domain spectroscopy （FDS） of oil-paper insulation ,we introduced the Havriliak-Negami （HN） dielectric relaxation model to research the characteristics of FDS. Analysis formulas of real and imaginary parts of HN dielectric relaxation model were solved based on the geometry method and complex analysis. FDS of five samples with different moisture content, temperature and DP of oil-paper insulation were determined.Moreover, HN dielectric re- laxation model were applied to fitting curves of FDS. The influences of moisture content, temperature and DP on parameters of HN dielectric relaxation model were analyzed. The results reveal that the relationships between relaxation time constant and moisture content, temperature, and DP satisfy the log-linear relationship, Arrhenius equation and linear relationship,respectively. High-frequency dielectric constant and its difference with static dielectric constant increase with the rising of moisture content, temperature, DP. Shape parameter β increases with rising of moisture content and tempera- ture, while decreases with fall of DP. The range of shape parameter a is 0.7~0.9.