考虑抱紧力退化和不同对接角度下的GIL触头温升特性

Temperature Rise Characteristics of GIL Contacts Considering Holding Force Degradation and Different Inserting Angles

气体绝缘输电线路(GIL)因高运行可靠性而得到广泛使用,但随着运行年限增长和载荷循环变化,其触头不可避免会出现接触劣化,进而引起过热故障。温升作为表征热故障演变的关键参量,论文由此出发,建立了GIL触头三维结构力学–温度–电磁场耦合模型,计算正常工况下触头的电流密度、接触电阻、接触压力和温度场分布;研究抱紧力退化时弹簧变化量与边界载荷、接触电阻、接触压力和最高温度的变化关系;基于不同对接角度下触头的温升特性和温度场分布,探索各触指的接触状态以及接触面电流密度、接触压力和接触收缩电导的分布规律。仿真实验及其分析表明:边界载荷和接触压力均与弹簧变化量成正比,而最高温度和接触收缩电阻的趋势均与前者相反;当对接角度大于1.5°时,触头可能存在接触失效且接触不良时的触指温升较大,而对接角度小于1°时各触指温升较小。

Gas insulated transmission lines are widely used for its high reliability.However,as the operational life grows and the load cycles change,its contacts may experience contact deterioration,which can easily cause overheating failure.The temperature rise is a key parameter to characterize the evolution of thermal faults.Based on the 3D mechanical-temperature-electromagnetic coupling model of GIL contact,the current density,contact resistance,contact pressure and temperature field under normal operating conditions are calculated.The holding force degradation is taken into consideration,and the relationship between spring deformation and boundary load,contact resistance,contact pressure and maximum temperature is studied.Then,based on the contact temperature rise characteristics and temperature field distribution at different inserting angles,the contact state and the distributions of current density,contact pressure and contact contraction conductance of each finger are analyzed.Simulation experiments and analysis show that the boundary load and contact pressure are proportional to the spring deformation,while the maximum temperature and contact contraction resistance have opposite trends.Otherwise,when the inserting angle is greater than 1.5°,the contacts may have contact failure and the temperature rise of fingers with bad contact is larger.However,the temperature rise of each finger is smaller when the inserting angle is less than 1°.