This paper describes the research on the electrical ageing mechanism of the resin-rich molding (RRM) insulation by the dielectric response method for large generator. The dielectric properties of the RRM insulation materials with different ageing time were measured and analysed by dielectric temperature spectrum, frequency-domain spectrum (FDS) and thermally stimulated depolarization current (TSDC). The microscopic properties of the main insulation material were also analysed by scanning electron microscope and dynamic mechanical analysis. The results of the FDS measurements showed that the dielectric loss factor \(\tan \delta\) and the real part ε of the complex dielectric constant of the main insulation material increased significantly in the frequency range of 10⁻²–10 Hz as the ageing time increased; the fitting results of the double relaxation HN (Havriliak–Negami) model indicated that DC conductivity and interfacial polarization increased by the electric ageing effect in the main insulation. When the test temperature exceeded the glass transition temperature, the relaxation process of turning-direction polarization changed in the main insulation system; the TSDC tests indicated that the energy levels of the deep and shallow traps were slightly reduced during the main insulation's ageing, but the number of traps increased; therefore, the ability of capturing and releasing charges was enhanced in the main insulation.

本文描述了通过大型发电机的介电响应法研究富树脂成型（RRM）绝缘的电老化机理。通过介电温度谱，频域谱（FDS）和热激发去极化电流（TSDC）对不同老化时间的RRM绝缘材料的介电性能进行了测量和分析。还通过扫描电子显微镜和动态力学分析来分析主要绝缘材料的微观性能。FDS测量结果表明，主绝缘材料的介电损耗因子\（\ tan \ delta \）和复数介电常数的实部ε在10 ^-2频率范围内显着增加–10 Hz随着老化时间的增加；双弛豫HN（Havriliak–Negami）模型的拟合结果表明，主绝缘中的电老化效应使直流电导率和界面极化增加。当测试温度超过玻璃化转变温度时，主绝缘系统中转向极化的弛豫过程发生了变化。TSDC测试表明，在主绝缘层的老化过程中，深陷阱和浅陷阱的能级略有降低，但陷阱的数量却增加了。因此，主绝缘中捕获和释放电荷的能力得到增强。