放电强度矢量不平衡法识别劣化绝缘子的研究

高压输电线路上的劣化绝缘子随时威胁着电力系统的安全。该文采用脉冲电流法检测三相绝缘子串的放电脉冲信号，在三相不平衡法的基础上提出了放电强度矢量不平衡法。该方法用放电强度矢量描述放电脉冲的分布，用放电强度矢量和、区域视在放电强度不平衡度作为辨识劣化绝缘子的依据。同时，采用C-均值聚类法排除偶然出现的异常统计信息，采用增量法解决三相绝缘子串固有的放电强度矢量不平衡问题。对110kV三相绝缘子串实验结果表明：用放电强度矢量不平衡法辨识劣化绝缘子是行之有效的。

IDENTIFYING FAULTY INSULATORS BY THE METHOD OF DISCHARGE STRENGTH VECTOR IMBALANCE

When there is any faulty insulator in high-voltage transmission, serious accidents may take place in power system at any moment. In the paper, the pulse current method is used to detect discharge pulses from three-phase insulator strings, and the analytical method of discharge strength vector imbalance based on the three-phase imbalance method is put forward. This method depicts the distribution of discharge pulses using discharge strength vectors, and identifies faulty insulators with the help of the sum of discharge strength vectors and the imbalance of apparent discharge strengths in different regions. At the same time, the C-mean clustering method is used to eliminate abnormal statistical information and the increment method to solve the asymmetry of the discharge strength vectors of normal three-phase insulator strings. The experiment results of 110kV three-phase insulator strings show that identifying faulty insulators by the method of discharge strength vector imbalance is effective.