特高压紧凑型输电线路工频电场强度计算

为研究特高压交流输电线路的工频电场强度,通过建立二维静电场有限元模型,计算了LGJ-400/65、LGJ-500/45、LGJ-630/45 3种型号导线,子导线根数分别为6、8、10、12的导线表面场强、相导线平均场强最大值、线路下方距地面1 m处最大场强和线路走廊宽度,分析了导线截面、子导线根数、线路最低对地高度和走廊宽度的选取。结果表明特高压交流线路选取大截面导线、紧凑型倒三角布置方式在导线表面场强、杆塔高度和线路走廊方面可满足要求。

Calculation of the Power Frequency Electric Field Intensity of UHV Compact Transmission Lines

UHV AC transmission lines can transmit large volume electric energy over a long distance;reduce number of circuit lines and corridor width.In order to solve the problem of energy unbalanced distribution,to construct a stable state power grid and allocate resources appropriately in China,UHV AC transmission lines is necessary.Corona loss,radio interference and audible noise are main parameters for the design of overhead transmission lines,these parameters are mainly decided by the maximum phase average EFI on conductors' surface.The maximum EFI at the level of 1 m above the ground under the line and the corridor width are also two critical parameters of transmission lines design.So the study of power frequency electric field intensity of UHV transmission lines is important.FEM is applied to the calculation of electric field intensity of UHV compact transmission lines.A two-dimensional electrostatic finite element model is set up,and the EFI on the surface of bundle conductors and phase average maximum EFI of UHV compact transmission line is calculated and comparison is made.The maximum EFI under the lines at the level of 1 m above the ground and corridor width is calculated and compared too.The selection of conductor section,number of bundle conductors,minimum distance of phase conductors above ground,corridor width is analyzed.Calculation and comparison result shows that UHV AC transmission lines with large conductor section,compact manner and inverse triangle configuration of phase conductors can satisfy engineering requirements.This conclusion can be a reference to the UHV transmission line design in China.