超高压输电线下复杂场景的工频电场分析

Power frequency electric field analysis of extra-high voltage transmission line under complex environment

为更准确地研究超高压输电线路下方存在复杂场景时的工频电场分布,该文采用模拟电荷法作为输电线下工频电场强度计算的主要计算方法。通过将模拟点电荷与线电荷结合,推导出适用于输电线下不同场景工频电场强度计算的公式。当输电线下存在建筑物、树木时,建立相应的简化模型。对离地1.5 m和建筑物顶部的平面内的电场强度进行仿真,发现建筑物墙体对其内部的工频电场起到屏蔽作用,在建筑物顶部电场强度会产生较大的畸变;输电线下存在树木时,树木会对工频电场起一定的屏蔽作用,树冠的大小会影响树木的屏蔽效果;在建筑物周围布置树木,发现树木对建筑物周围的畸变电场有明显削弱作用。计算结果可为输电线下方存在建筑物和树木时的工频电场强度分析提供依据。

In order to more precisely research the power frequency electric field of complex environment below the EHV transmission line,the paper adopted charge simulation method as the main method for power frequency electric field intensity calculation below transmission line.By combining the simulation point charge with the line charge,a formula used for the power frequency electric field intensity calculation in different environment below the transmission line was deduced.Corresponding simplified models of buildings and trees(if any)below the transmission line were set up.Through the simulation of the electric field intensity which was 1.5 m away from the ground and within the plane at the top of building,it was found that the building wall has shielding effects on its inner power frequency electric field.The electric filed intensity at top of building had a great distortion.If there had trees under the transmission line,the trees could have certain shielding effects on power frequency electric field intensity and the size of the crown could affect the shielding effect.If trees were arranged around the building,it found that the trees could weaken the distortion of electric field intensity around the building significantly.The calculation results provide reference for the power frequency electric field distribution when there are buildings and trees under the transmission line.