500kV线路耐张复合绝缘子安全系数的选取

Safety Coefficient of Composite Insulators Tension Strings for 500 kV AC Transmission Lines

500kV线路的传统盘形瓷耐张绝缘子过于沉重、抗污闪性能不足、零值和经济性能差的问题越来越突出,需要采取新的技术措施。复合绝缘子以其重量轻、机械强度高、防污闪性能好等优点,已经在电力线路中的悬垂串中取得了良好的效果,解决其安全系数的选取问题是复合绝缘子应用于500kV线路耐张串上的关键问题。为此,从对比研究的思路出发,运用架空导线非线性动力学的分析方法,分析比较耐张复合绝缘子和悬垂复合绝缘子在动态力下的冲击系数。结果表明在断联、脱冰跳跃、舞动、台风等动态力作用下,耐张复合绝缘子的总体动态力冲击系数不大于悬垂复合绝缘子,得出结论:耐张复合绝缘子的安全系数与悬垂复合绝缘子一样取3是合适的。

The traditional porcelain tension insulators for 500 kV AC transmission lines have a lot of disadvantages such as overweight,ill performances of pollution flashover,faulty insulators,and low economic benefit,so new technological measures should be taken.Due to excellent pollution flashover performance,light weight,and high mechanical strength,composite insulators are widely used as suspension strings on high voltage transmission lines.The key problem of composite insulators tension strings is the safety coefficient.By comparative study,we used the nonlinear dynamic analysis method on the overhead transmission line,and calculated the dynamic action force of composite insulators tension strings,under string-breaking,ice-shedding,galloping and typhoon.Result shows that,the impact coefficient of tension strings is not higher than that of suspension strings,so the safety coefficient 3 of composite insulators tension strings is reasonable.