研究了基于Havriliak-Negami模型的受潮套管分布式频域介电谱测量方法，并评估了套管受潮状态。利用分布式频域介电谱测量方法，分析了在0. 1 Hz和1 Hz频率下不同含水量套管模型介损随测试电压的变化规律，以及内外层受潮套管介质损耗角正切值的分布规律，利用Havriliak-Negami模型拟合了不同含水量油浸式受潮缺陷套管频域介电谱参数。试验结果表明，随电压升高，含水量越大的套管，低频介损线性增加幅度越大；弛豫时间常数随水分含量增加而减小，水分含量满足对数线性关系；末屏接头与套管次末屏之间电容实部对套管外层受潮非常敏感；导杆-次末屏电容对套管内层受潮非常敏感，确定受潮部位对套管受潮诊断具有重要意义。

A distributed frequency domain dielectric spectrum measurement method based on Havriliak-Negami model is studied to evaluate the wet state of casing. Based on the distributed frequency domain dielectric spectrum measurement method, the variation of dielectric loss of casing model with different water content under 0.1 Hz and 1 Hz frequency and the variation of dielectric loss tangent value of inner and outer layer wetted casing are analyzed. The frequency domain dielectric spectrum parameters of oil immersed casing with different water content are fitted by Havriliak-Negami model. The results show that with the increase of voltage, the higher the water content, the greater the linear increase range of low frequency dielectric loss of casing; the relaxation time constant decreases with the increase of water content, and the moisture content meets the logarithmic linear relationship; the capacitance between the end shield joint and the secondary end shield of the casing is not always sensitive to the moisture in the outer layer of the casing; the capacitance between the guide rod and the secondary end shield is very sensitive to the moisture in the inner layer of the casing, determining the damp location is of great significance to the diagnosis of casing damp.