雷击建筑物分流计算

Calculation of Current Distribution in a Building under Lightning Strike

通常按照标准GB/T19271.1、GB50057对雷击建筑物后雷电流分配的计算,是一种非常粗略的估算方法。连接建筑物的服务设施很多,如金属水管,煤气管,电话线,电力线等设备都会起到分流的作用,建筑物的接地电阻、配电系统的配电型式、变压器与建筑间的线路类型和距离等都会影响到雷电流的分配。就这些问题展开了研究。具体来说,在EMTP电磁暂态仿真计算程序基础上,针对我国低压电源系统的TT配电型式,在雷击建筑物防雷装置的情况下对雷电流分配进行计算和详细分析,最后得出建筑物的接地电阻和变压器与建筑物的距离对雷电流在建筑物的接地系统、相线和中性线的分配具有较大影响的结论。

Unusually calculation of current distribution in a building under hghtning stroke mentioned in the criteria GB/ T19271.1 ,GB50057 is a rough method. Facilities in a building including metal pipe, gas pipe, telephone line, power line can distribute current. Also, building＇s grounding resistance, distribution mode, distance between transformer and building would influence current distribution. Considering TT distribution mode of low-voltage source system, current distribution calculated based on EMTP electromagnetic transient simulation. As a result, grounding resistance and distance between transformer and building have influence on current distributes in grounding system, phase conductor, and neutral line.