电晕决定输电线路的电磁环境特性。采用模拟电荷法计算交流输电线路的电晕损失,交流导线用多根线电荷表示,导线表面场强超过起晕场强时令一定量电荷由导线表面发射到空间中。将交流周期分为若干时段,在每一时刻都考虑了导线表面电荷发射、空间电荷运动、空间电荷复合等效应,重复计算若干周期直至离子流场稳定。在已有方法的基础上改进了起晕条件和电荷发射的计算方法,考虑了导线表面电场不均匀性对电晕放电的影响,从而可以对多相多分裂导线离子流场进行仿真计算,进而计算得到线路电晕损失。对三相8分裂特高压交流线路电晕损失计算结果与试验结果有较好的一致性。
Corona determines the electromagnetic environment characteristics of transmission line. In this paper, the corona losses calculation method of AC transmission lines based on charge simulation method is improved. The AC conductors are represented by discrete infinite line charges. When the value of conductor surface electric field exceeds the onset value, some ration charges emit to the space from the conductor surface . The AC cycle is divided into some durations. In each discrete time step the conductor surface charge emission, space charge displacement, space charge recombination were repeatedly calculated for some periods until the ionized field stable. The major contribution of this paper is the algorithm improvement on corona onset criterion and charge emission. The influence of the conductor surface field uniformity on corona discharge was counted in, so that the ion flow field of multi-phase or bundle conductors can be simulated and the lines corona losses can be obtained. The corona losses, of a 3 phases 8 bundle conductors HVAC transmission line was calculated and the calculation result was compared with the experimental result.