超特高压交流输电线路电晕对地面电场的影响

为研究超特高压交流输电线路电晕放电对地面电场的影响,改进了基于模拟电荷法的交流线路下离子流场计算方法,并将其应用在交流线路下地面电场的计算中。所提出的改进方法考虑了导线表面电场不均匀性对电晕放电的影响,从而可对多相多分裂导线离子流场进行仿真计算。对三相8分裂1000kV交流线路的地面电场的计算结果表明,对典型1000kV三相交流输电线路参数,考虑电晕时的地面电场比不考虑电晕时增加约5%。子导线半径、分裂间距、分裂根数、相间距、线路高度等线路参数变化时电晕对地面电场有不同程度的影响。

Influence of Corona Effect on Ground Level Electrical Field Under EHV/UHV AC Transmission Lines

Corona decides the electromagnetic environment characteristics of transmission line. It is generally considered that the space charges produced by corona discharge are restricted in the vicinity of AC transmission lines and rarely affect the ground level electrical field. So,the corona effect is usually neglected in the calculation of ground level electrical field under AC transmission lines. However,this theory needs to be proved. In this paper,the charge simulation method (CSM) based ion flow field calculation method is improved and applied into the calculation of ground level electrical field under AC transmission lines. The influence of the conductor surface field uniformity on corona discharge is counted in,so that the ion flow field of multi-phase or bundle conductors can be simulated. The ground level electrical field considering corona effect under a 3-phase 8-bundle conductor 1000kV AC transmission line is calculated. The calculation results indicated that the corona discharge enhances the ground level electrical field,and the enhancement ratio is about 5% for typical 3-phase 1000kV AC transmission lines. The influence of line parameters such as bundled conductor radius,split conductor spacing,split conductor number,wire spacing and phase height on ground level electrical field are discussed.