基于有限元的输电线路避雷器放电能量研究

Study on the Discharge Energy of Surge Arrester on Transmission Lines Based on Finite Element

为了减少由于超压放电时所产生的高能量引起避雷器特性的劣化率,通过有限元分析法建立一组不同尺寸和额定值的输电线路避雷器模型,并研究其在快波前浪涌事件中释放能量的能力。结果表明,有限元法模拟结果与PSCAD/EMTDC、EMTP-RV软件的模拟结果基本一致;采用模型计算得出的放电电压和能量承受能力与PSCAD/EMTDC、EMTP-RV软件的模拟结果及制造商提供的测试数据基本吻合,证明所建立的模型适于所研究的工况;另外,通过所建立模型,进行了参数分析,发现ZnO块的高度和直径的变化对单脉冲电流注入期间避雷器的放电能量能力产生显着影响;改变绝缘层的厚度和介电常数显着影响避雷器内部的电场分布的均匀性而非放电能量能力。

In order to reduce the degradation rate of arrester characteristics due to high energy discharged by the overvoltage,a set of models with different sizes and ratings are established by analysis method,and the ability to release energy in the fast wave pre-surge event is studied.The results show that the finite element method simulation results are basically consistent with the simulation results of PSCAD/EMTDC and EMTP-RV software;the discharge voltage and energy withstand capability calculated by the model is basically consistent with the simulation results of PSCAD/EMTDC and EMTP-RV software,and also with manufacturers’data.Parametric analyses were also conducted using finite element method to study the effects of varying the design geometry of the ZnO blocks.It was found that variation in the height and diameter of the ZnO block results in remarkable effects on the discharge energy capability of the arrester during single impulse current injection.Meanwhile,varying the thickness and dielectric constant of the insulation layer significantly affects the uniformity of the electric field distribution inside the arrester rather than the discharge energy capability.