母线槽配电干线周围的工频磁场

Numerical and Experimental Evaluationof Power Frequency Magnetic Fieldsaround Busbar Trunking Systems

母线槽在建筑物特别是高层建筑物的配电系统中常被用于配电干线。这种重载流配电干线周围的工频磁场近年来引起了人们的关注。笔者用边界元数值计算和实验测量方法分析母线槽周围的工频磁场。对铁外壳母线槽提出了等效相对磁导率处理方法,并证明其可行性和有效性。发现铁外壳材料的等效相对磁导率和母线槽所载的电流基本上成正比。对工程中常用的镀锌铁皮外壳空气绝缘母线槽、铜芯铝壳和铝芯铁壳全封闭母线槽周围的磁场进行了计算和测量。对母线槽周围的谐波磁场也进行了讨论。

Busbar trunking systems are often employed as risen in building distribution systems.The power frequency magnetic fields from such risers are of concern in recent years. Based on numerical simulations and laboratory experiments, the paper addresses power frequency magnetic field distributions around busbar trunking systems. Magnetic fields around typical busbar trunking and busducts are investigated and compared with limits in correlated international standards. Iron or galvanized iron trunking of the busbar trunking system is approximately modeled as linear trunking with a constant equivalent relative permeability. The effectiveness of such modeling method is validated.It is found that the equivalent relative permeability is almost linearly proportional the magnitude of the current carried by the busbar trunking system. Harmonic frequency magnetic fields around busbar trunking systems are also discussed.