超高压输电线工频电场计算的矩量法和表面电荷混合法

结合矩量法和表面电荷法各自的优点,提出一种用矩量法—表面电荷法相结合的混合算法来计算复杂场景下超高压输电线工频电场的分布,通过综合考虑输电线路的弧垂、分裂导线等因素,建立了复杂场景下超高压输电线的三维模型,并进行了相应的计算。结果表明:该混合法具有提高计算速度,减少占用内存和避免模拟点电荷设置等优点。对于所述的树状物模型,树状物对其下方离地1.5 m处工频电场起屏蔽作用。树状物尺寸参数的变化对其下工频电场分布影响明显,树冠半径越大其屏蔽范围越大,树干高度越高其屏蔽强度越弱。相间距和输电线高度的变化对电场值基本无影响。混合法可为高压输电线路在复杂场景下工频电场分析提供重要的参考。

Power-frequency electric field calculation of extra high voltage transmission lines by means of the mixed method combining MOM and SCM

In order to study the power frequency electric field generated by the extra high voltage(EHV) transmission lines under the condition of complex scenes,the mix method combining the method of moments and surface charge method is proposed.This method combines the advantages of both approaches,which can rapidly and accurately calculate the distribution of the power frequency electric field around the complex scenes.The sags and number of bundled conductors of the transmission line are considered.An accurate three dimensional calculation model was established.Then the power frequency electric field distributions was calculated in the paper.The simulation results show that the hybrid method,which can evidently increase speed and reduce memory,is used to calculate the power frequency electric field distribution under the condition of complex scenes.In addition,for the model of tree in the paper,because of the presence of tree,the values of the power frequency electric field off the ground 1.5m are shielded beneath the tree.The tree parameters changing has an obvious influence on the distribution of power frequency electric field.The larger the radius of crown is,the more extensive the shielding range becomes.The higher the height of trunk is,the weaker the shielding capacity becomes.The value of electric field beneath the tree isn′t changed when the phase spacing and the height of the EHV transmission lines are changed.The proposed method is available for reference to the power frequency electric field analysis of EHV transmission lines when it passes through the complex scenes.