基于孔缝箱体屏蔽效能的研究

Research on Shielding Effectiveness of Box with Aperture

变电站二次侧敏感设备在检测过程中易受到电磁干扰,测得准确数据变得非常困难。机箱电磁屏蔽是一种有效的电磁屏蔽措施,在电气设备外部加装金属罩作为机箱外壳以提高电磁屏蔽性能。基于屏蔽效能定义进行讨论,对材料选取进行分析,考虑到设备散热对机箱开设孔洞,根据孔洞的形状、大小等做了一系列对比分析。结果表明:不同金属材料以及孔缝都对机箱屏蔽效能产生影响,不锈钢比铜屏蔽效能略好,孔缝对机箱屏蔽影响较大。通过ANSYS进行模拟仿真,对比分析结果选出最优解并给出相应措施方案。

It is difficult to get accurate data because the secondary sensitive equipment of substation is susceptible to electromagnetic interference.Case electromagnetic shielding is a very effective electromagnetic shielding measures,which means a metal cover is added to the external electrical equipment as a metal housing to improve the electromagnetic shielding performance.This paper discussed the definition of shielding effectiveness and then analyzed the material selection.Considering the opening of holes in the chassis for the cooling of equipment,a series of comparative analyses were made according to the shape and size of holes.The results showed that different metal materials and holes had an effect on the shielding efficiency of chassis,for example stainless steel was slightly better than copper,and holes had a greater effect on the shielding efficiency of chassis.Through the simulation of ANSYS,comparison and analysis the results,the optimal solution was selected and corresponding measures are given.