中文摘要：

劣化绝缘子的存在会直接威胁到电力系统的安全运行。以仿真和实验室试验相结合的方法，分析悬垂瓷绝缘子串中有／无劣化绝缘子时的空间电场分布特性，着重分析了测量距离、劣化绝缘子位置和片数及其型式、污秽对悬垂绝缘子串空间轴向电场的影响。结果表明：劣化绝缘子对空间轴向电场分量影响最大；测量距离越远，其空间轴向电场的变化率越小；劣化绝缘子位置靠近高压端时，其空间轴向电场变化率增加，中间位置时最小且基本不变，靠近低压端时又略微增加；2片绝缘子连续劣化比不连续劣化引起空间轴向电场变化率大；对于220kV线路悬垂串只需分析低压端的3片绝缘子空间轴向电场变化率就可判断出串中是否含有零值绝缘子。因此，直接分析绝缘子串空间轴向电场的变化能够判断出劣化绝缘子及其位置。

英文摘要：

Existence of deteriorated insulators is a direct threat to the safety of power system operation. With the method combining simulation analysis and laboratory test, the space electric field distribution of overhang porcelain insulator string with and without deteriorated insulator was analyzed, and the analysis was focused on the influence of measurement distance, position, type and number of deteriorated insulators, and pollution on the space axial electric field distribution of overhang string. Study showed： deteriorated insulator had the greatest effect on the axial electric field of insulator string; the measurement distance farther, the rate of the axial electric field changed smaller; the rate of axial electric field change increased with the deteriorated insulator approaching the high-voltage end, became the smallest and almost stayed constant in the middle position, and had a slight increase near to the low-voltage end; the rate of axial electric field change with two adjacent deteriorated insulator was greater than that with two separate deteriorated insulator; just by analyzing axial electric field change rate of three insulators in the low-voltage end of the 220 kV overhang string, we can determine whether it contains a zero-value insulator. Therefore, the deteriorated insulator and its position can be detected by analyzing the space axial electric field change of insulator string directly.