35～1000kV线路绝缘子污闪电压值的估算

针对目前绝缘子污闪电压缺乏系统研究的现状,建立了35~1 000 kV输电线路用普通型绝缘子交流污闪电压的计算模型即展开普通型绝缘子成平面模型后分析交流污闪条件,计算出绝缘子在不同表面污层电导率条件下的临界污闪电压值;对35~1 000 kV输电线路用5种不同吨位的普通型绝缘子进行交流人工污秽试验,获其在各盐密下的50%污闪电压;通过计算值和试验值的对比,可将绝缘子表面污层电导率转化为盐密,从而算出各普通型绝缘子在不同盐密下的交流污闪电压值。试验验证计算结果误差小,说明该模型能够有效估算代表普通型绝缘子的50%污闪电压情况。该研究结果可供各电压等级输电线路外绝缘选择参改。

Calculation of Pollution Flashover Voltage of Insulators for 35～1 000 kV Transmission Lines

A calculated model for pollution flashover voltage of AC normal insulators is established.First,a flat plate model is suggested for suspension ac normal insulators.According to analyzing the ac pollution flashover condition,the critical arc length and the resistance of residual contamination layer in the insulator pollution flashover progress were calculated based on this model.Then the critical flashover voltage of insulators can be figured out in different contamination layer conductance.The 50% flashover voltage of five types of insulators can be obtained from artificial contamination test.By comparing the calculated value and the test value,the contamination layer conductance can be transformed to equivalent salt deposit density(ESDD),and the pollution flashover voltage in different ESDD can be figured out.For an ac normal insulator,if the main configuration parameters and the ESDD on the surface are known,the critical pollution flashover voltage can be figured out.In the end,the artificial contamination tests have validated the reliability of the calculation model.The work result can be used for the external insulation selection of power transmission line.