试验方法对复合绝缘子污秽闪络特性的影响

Influence of Test Methods on Pollution Flashover Performance of Composite Insulators

IEC及中国相关标准推荐了几种绝缘子污秽的试验方法,但不同试验方法对复合绝缘子污闪特性的影响并不明确。以复合绝缘子为例,分别采用恒压升降法、均匀升压法、最大耐受法试验研究了复合绝缘子的交流污秽闪络特性。结果表明:试验方法对污秽影响特征指数a值的影响不明显;在标准偏差取7.0%时,采用均匀升压法得到的50%闪络电压比采用恒压升降法得到的50%耐受电压高0.5个标准偏差,采用最大耐受法得到的最大耐受电压Umw等于采用恒压升降法得到的闪络概率为10%的污闪电压;不同的试验方法得到的试验结果存在内在联系,可以根据试验的具体情况,选择适当试验方法。

Different methods for testing pollution flashover performance are recommended in IEC and Chinese standards, but the differences among the test methods are not pointed out. In this paper, the pollution flashover performance of composite insulator is tested with uniform increase voltage method, 50% withstand voltage method, and maximum withstand voltage method, respectively. The results indicate that the influences of different test methods on the index value a are not obvious. For the standard deviation of 7.0% ,the 50% flashover voltage from uniform increase voltage method is 0.5 standard deviation higher than that from the 50% withstand voltage method,the maxium withstand voltage Umw is equal to the flashover voltage from the uniform increase voltage method with a flashover probability 10%. It is concluded that there exist internal relations among the results from different test methods, so appropriate test method may be chosen according to specific situation of test.