应用有限元法计算氧化锌避雷器电位分布

应用有限元法计算了具有开域边界的氧化锌避雷器的电位分布。通过设置人工截断边界，将开域电场问题转化成有界域电场问题，并在人工截断边界上采用渐近边界条件。对于氧化锌避雷器中存在大量的电位悬浮导体问题，则采用虚拟齐次强加边界法加以解决。对330kV和500kV氧化锌避雷器电位分布进行了计算和测量，结果验证了该文方法的正确性和有效性，并得出以下结论：随着安装高度的增加，阀片分布将趋于均匀；在高压端加装均压环会大大降低阀片的最大电位承担率，改善阀片的电位分布。与基于模拟电荷法的其它方法相比，该文方法简单、通用，可以充分利用已有的有限元计算程序，很好地满足了工程应用和设计的需要。

CALCULATION OF POTENTIAL DISTRIBUTION FOR ZINC-OXIDE SURGE ARRESTER BY FINITE EIEMENT METHOD

Finite element method (FEM) is applied to the calculation of potential distribution for ZnO surge arrester with open boundary. The open boundary field problem is transformed to the bounded field problem through setting artificially truncating boundary with asymptotic boundary condition. The vitual homogeneous imposed boundary is presented to deal with a great number of floating conductors in the surge arrester. The potential distributions of 330 kV and 500 kV ZnO surge arrester are calculated and measured. The numerical results show that the method is correct and efficient. Some conclusions are also concluded as follow. The potential distribution of ZnO elements tends to be uniform with the increase of mounting height. The maximum ratio of born potential will be decreased greatly in presence of equalizer ring so that the potential distribution of ZnO elements could be improved. Compared with other methods based on simulation electric charge, our method is advantageous for its simplicity,generality and sufficient utilization of existing program. It can well satisfy the demands of engineering design and application.