输电线路绝缘子、金具和导地线可靠度校准

Reliability Calibration of Insulator,Fitting and Ground Wire in Transmission Line

为确定跨越高速铁路输电线路的可靠度水平,分析确定了绝缘子、金具和导地线的荷载、抗力的统计参数,采用考虑基本变量概率分布类型的一次二阶矩方法对按现行规范设计的输电线路的绝缘子、金具和导地线的可靠度进行了校准。分析表明,绝缘子串的可靠指标与绝缘子的联数及一联中绝缘子的数目有关。一联中绝缘子的数目按50考虑时,单联的平均可靠指标为3.45,双联为3.55。金具的平均可靠指标为3.55。对于导地线,永久荷载与风荷载组合时,弧垂最低点和悬挂点的平均可靠指标分别为4.90和4.45;永久荷载、风荷载与覆冰荷载组合时,弧垂最低点和悬挂点的平均可靠指标分别为4.55和4.15。与杆塔结构相比绝缘子、金具和导地线具有较高的可靠度水平。

To set the reliability level of transmission line crossing high speed railway,the statistical parameters of the load and resistance of insulators,fittings and ground wires were analyzed and determined.And the reliabilities of these members designed based on the current code were calibrate by using FOSM（first order second moment） method with considering the probability distribution type of basic variables.It is indicated that the reliability index of insulator string depends on the parallel number of strings and the number of insulator in one string.The reliability indexes of single and double insulator string with 50 insulators in one string are 3.45 and 3.55 respectively.The average reliability index of fittings is 3.55.The reliability index of ground wire at the sag＇ s lowest point or suspension point are 4.90 and4.45respectively,in the combination of permanent load and wind load;and 4.45 and 4.15 respectively,in the combination of permanent load,wind load and ice load.The reliability indexes of insulators,fittings and ground wires are larger than that of transmission tower.