考虑复杂山地风加速的架空线路风偏闪络故障分析

Flashover Fault of Overhead Transmission Lines Caused by Windage Yaw Considering the Speed up of Wind Velocity Under Complex Mountainous Terrain

针对近期某省内发生的一起在复杂山地地形下的220 kV输电线路闪络放电故障,结合现场实际数据对故障的情况进行分析。首先依据现场实际地形、杆塔和气象数据,采用未考虑地形风速影响的传统设计计算方法得到线路故障段风偏位移,所得风偏后的放电间距满足导线设计安全距离要求;而后利用自主研发的Transpert输电线路专家系统中的高程数据建立现场实际复杂山地地形的三维模型,通过ANSYS有限元风场仿真得到故障点风速分布,并计算得到地形风速加速影响后的输电线路风偏角,发现考虑山地风速加速后的风偏放电间距小于安全距离,相比传统计算更符合实际现场情况,验证了山地地形因素对线路风偏计算存在的影响。

In view of a flashover fault of 220 kV overhead transmission line under complex mountainous terrain in a province recently,theauthor analyzes the situation of the fault combining with the actual data.Firstly,according to the actual terrain,tower and meteorological data of the site,the windage yaw displacement of the fault section of the line is obtained by using the traditional design calculation method without considering the impact of terrain wind speed,and the discharge distance after the wind deflection is greater than the safe distance of 220 kV conductor;then,the three-dimensional model of the complex mountainous terrain is established by using the data in the transmission line expert system(Transpert)which is self developed,and the wind speed value at the fault section is obtained through ANSYS finite element wind field simulation analysis.The wind deflection angle of the transmission line after the acceleration of the terrain wind speed is calculated.It is found that the wind deflection discharge distance after the acceleration of the mountain wind speed is less than the safe distance,which is more in line with the actual situation than the traditional calculation,and verifies the influence of the mountain terrain factors on the wind deflection calculation.