中文摘要：

水分会导致油纸绝缘电气性能下降并加速老化,但是水分对油纸老化过程中空间电荷特性的影响鲜有报道。本文利用电声脉冲（PEA）法研究了不同老化阶段、不同含水量油纸中的空间电荷特性,结果表明当含水量较低时,增加含水量可以加速空间电荷到达稳态,但是进一步增加含水量反而会减速;老化初期的油纸主要以异极性电荷积聚为主,而随着老化程度的加剧,逐渐演变为同极性电荷注入。随着含水量的增加,需要更长的老化时间电荷注入类型才会发生变化,继续增大含水量将加速注入类型的转变。分析认为水分一方面会加速老化,加剧空间电荷积聚,另一方面会加快或减缓空间电荷到达稳态的过程,所以电荷注入类型会发生转变,转变时油纸中的空间电荷会很快到达稳态,阳极附近空间电荷积聚变少,电场畸变程度小。

英文摘要：

Moisture can lead to the electrical property degradation of oil-paper insulation and accelerate the aging of oil-paper. However, few studies of the influence of water concentrations on the space charge characteristics of thermally aged oil-paper insulation are reported. Therefore, we used the pulsed electroacoustic （PEA） method to determine the space charge characteristics of oil-papers with different moisture at different aging stages. The results show that the formation of space charge equilibrium in oil-paper is accelerated when water concentration is small, but it gets slowed down if the wa- ter concentration is high. At the beginning of thermal aging, heterogeneous charge accumulation takes predominance in oil-paper, but it gradually changes into homogeneous charge injection as thermal aging processing. This transformation of charge injection type takes more time with increasing water concentration in a certain range, otherwise the transformation progress is faster. It is believed that moisture concentration accelerates aging and enhances charge accumulation on the one hand, while it speeds up or slows down the establishment of space charge on the other hand, so the charge injection type changes with aging. When the charge injection type changes, the space charge in oil-paper will quickly reach a sta- tionary condition, namely, the space charge accumulation near anode decreases, and the electric field distortion becomes less.