避雷线预绞丝端口的电磁损耗分布分析

避雷线预绞丝端口所产生的电磁损耗是预绞丝端口高温的主要热源,局部高温可能导致避雷线发生损伤.基于避雷线与预绞丝之间接触点的实际分布特征,利用Comsol有限元分析软件构建预绞丝端口的三维电磁场仿真模型.通过仿真计算得到预绞丝端口的电磁损耗密度分布,并进行分析讨论.结合稳态温升实验与接触电阻测量实验对仿真模型的准确性进行验证.基于该仿真模型,探究了预绞丝端口电磁损耗与钢的相对磁导率和绞线绞合参数之间的关系.研究结果表明,仿真模型具有足够的准确性,误差没有超过8%.预绞丝端口的电磁损耗主要集中于避雷线与预绞丝之间的接触点,各排接触点的电磁损耗随着轴向距离的增加逐步递减.此外,预绞丝端口的电磁损耗与钢的相对磁导率、相邻接触点的轴向距离呈正相关.

Analysis on Electromagnetic Losses Distribution of Armor Rod Segment of Lightning Wire

The electromagnetic losses generated at the armor rod segment of lighting wire are the main heat source for the high temperature of armor rod segment. The local high temperature may cause damage to the lightning wire. Based on the actual distribution characteristics of the contact points between the lightning wire and armor rod, a three-dimensional electromagnetic field simulation model of armor rod segment was established by Comsol. The electromagnetic losses density distribution of armor rod segment obtained by simulation was analyzed and discussed. Subsequently, the steady-state temperature rise experiment and the contact resistance measurement experiment were combined to verify the accuracy of the simulation model. Based on the simulation model, the relationship between the electromagnetic losses of armor rod segment and the relative permeability of steel and twisting parameters of stranded wires was explored. The research results show that the simulation models are accurate enough and the error is less than 6%. The electromagnetic losses of armor rod segment are mainly concentrated on the contact points between lightning wire and armor rod. The electromagnetic losses of each row of contact points gradually decrease with the increase of the axial distance. In addition, the electromagnetic losses of the armor rod segment are positively related to the relative permeability of steel and the axial distance of adjacent contact points.