架空线路上场线耦合感应电压计算中杆塔迎面先导高度的影响研究

Study the Upward Leader Height Influence of Transmission Tower to Overhead Lines Induced Voltage as Stoked by Direct Lightning

雷击通道电磁场对架空线路耐雷水平的影响是与杆塔或雷击物的迎面先导高度有关的,采用IEEE推荐的雷击电磁场数值计算程序,计算分析了不同高度迎面先导时架空线路上的感应电压,通过与实际运行的情况对比,确定了不同杆塔高度,其迎面先导高度不同,相应的感应电压计算公式不同。虽然迎面先导高度也与雷击电流大小有关,但在同样大小雷击电流情况下,必须有针对性地采用与杆塔高度相适应的迎面先导高度,才能计算出合理的感应电压。

The influence of the lightning channel electromagnetic field to the lightning critical current of transmission lines is much related with the upward leader height of stroked transmission tower or the elevated subject. Based on the numerical electromagnetic field computation code, the induced voltage on overhead transmission lines with different upward leader height is calculated by contrasting with the engineering practice, varying transmission tower height have different upward leader height. So it will have different induced voltage calculation formulae with different tower height. Although the lightning magnitude determined the upward leader height also, with one lightning current size, the upward leader must be on the speaking terms with its tower height. Then the rational induced voltage can be computed.