特高压大跨越架空线路三维工频电场计算

3D Power Frequency Electric Field Calculation of Multi-span UHV Overhead Line

1000kV特高压输电线路跨越江河时,线路的档距和弧垂均较大,为了解线路周围的电场确定线路最小对地高度,引入线性单元模拟电荷法,同时考虑铁塔的影响,根据悬链线方程建立了特高压大跨越线路的模型,采用三维电场的计算方法计算了线路周围的工频电场分布。三维电场方法与二维电场方法的计算和对比分析结果表明:对于特高压普通架空线路,采用二维电场方法与采用三维电场方法所得的计算结果基本相等,均可满足工程要求;对于特高压大跨越线路,采用三维电场方法计算可以更准确地反映大跨越线路的电场分布,提高工程的设计精度。

When the 1000 kV UHV overhead line goes across the river, the span is very long and sag is higher, the three-dimensional method is applicable to this case. This paper proposes an effective 3D charge simulation method which is based on finite slant line charges to calculate the electric field in the vicinity of multi-span UHV overhead lines. Each line is subdivided into smal segments, of which the position is specified according the catenary equation, the tower is modeled too. Each segment is represented by linear charges. The comparison of the results from the 2D and 3D methods show that, on transmission line ,the 2D method can acquire accurate value when calculating the electric intensity at the middle span,wheras,when calculating the electric intensity in the vicinity of multi-span UHV overhead line, the 3D method is proved to be quite effective and more accurate.