材料期刊网

为评估油纸老化状况，通过加速热老化试验制备了3种不同老化程度的油纸绝缘样品，对其进行相关理化参数的测量，确定3种样品分别处于老化初期、末期和中期；然后对其进行吸潮试验，得到9种不同老化、水分组合的油纸绝缘样品；再进行频域介电谱测试得到介电谱；最后对介电谱进行分析，研究不同水分含量、不同老化程度分别对频域介电谱的影响。结果表明：随着油纸绝缘水分含量的上升，复介电常数的实部和虚部都有增加；水分对频域介电谱的影响体现在整个频率范围内，但低频时影响更加明显；随着老化程度的加剧，复介电常数的实部和虚部都有增加，但其对频域介电谱的影响主要集中在低频区域。通过对比各样品的测试结果，发现其中几种不同老化、水分组合的样品具有相似的介电谱。说明用频域介电谱法进行绝缘评估时有必要引入一定的补偿方法，以保证评估结果的可靠性。

In order to evaluate the ageing condition of oil-paper, three oil-paper insulation samples with different ageing degree were prepared through accelerated thermal ageing test. Their physical and chemi-cal parameters were measured to ensure that they were in the initial, middle, and end stage of ageing re-spectively. Then nine oil-paper insulation samples with different ageing and moisture combination were ob-tained through moisture absorption test, and their frequency domain dielectric spectra were obtained by FDS. Finally, the effects of different moisutre content and different ageing degree on the frequency do-main dielectric spectra were anlyzed. The results show that with the increase of moisture, the real part and imaginary part of complex permittivity both increase, and the effect of moisture on the frequency do-main dielectric spectra is more obvious in the low frequency region. With the increase of ageing degree, the real part and imaginary part of complex permittivity both increase, and the effect of ageing on the frequency domain dielectric spectra mainly concentrates upon the low frequency region. It is found that the frequency domain dielectric spectra of different samples with different ageing and moisture combina-tion are similar. Therefore, it is necessary to introduce some compensation methods to ensure the reliabili-ty of evaluation results when using FDS to evaluate the insulation condition.