500 kV输电线路低零值绝缘子对绝缘子串电压分布的影响

Influence of Low and Zero Resistance Insulators on Voltage Distribution of Insulator String in 500 kV Transmission Lines

为了研究低零值绝缘子对绝缘子串电压分布的影响,以30片绝缘子构成的500 kV输电线路用绝缘子串为研究对象,利用MATLAB对其电路模型进行仿真分析。结果表明:绝缘子的绝缘电阻低于500 MΩ和分布电压值低于50%的标准参考值这两种判别低零值绝缘子的方法之间没有直接的对应关系;当低零值绝缘子的绝缘电阻下降为500 MΩ时,其自身分布电压的下降程度可以忽略不计,而当低零值绝缘子的绝缘电阻下降为30 MΩ时,其自身分布电压下降约50%。

In order to study the influence of low and zero resistance insulator on the voltage distribution of insulator string, an insulator string composed of 30 pieces of insulators for 500 kV transmission line was taken as research object, and its circuit model was simulated and analyzed by MATLAB. The results show that there is no direct correspondence between two methods for judging the low and zero resistance insulators, one judging method is insulation resistance lower than 500 MΩ, and another judging method is distribution voltage lower than 50% standard value. When the insulation resistance of low and zero resistance insulator drops to 500 MΩ, the dropping degree of its distribution voltage can be ignored. However when the insulation resistance of low and zero resistance insulator drops to 30 MΩ, its distribu- tion voltage drops about 50%.