新型接触网腕臂绝缘子积污特性数值分析

Numerical Analysis of Contamination Characteristics of New Type Insulator for Catenary Cantilever

为解决兰新高铁达坂城盐湖风区接触网绝缘子大面积污闪问题,设计了新型接触网腕臂绝缘子,根据工频复数电磁场理论和计算流体力学理论,在COMSOL Multiphysics仿真平台上构建了电场─流场─粒子追踪场─流体和粒子相互作用的多物理场单相耦合的等比例绝缘子风洞积污仿真模型,以碰撞系数和分布系数为表征参数,分析了不同气流角度下绝缘子表面积污特性。结果表明:当气流角度从0°~±45°变化时,绝缘子表面碰撞系数随着粒径的增大而增大;同一粒径下,伞裙表面分布系数符合正“γ”形分布,杆径和金具表面分布系数符合倒“γ”分布;在电场强度转折点处加装超大伞裙的新型绝缘子,有效降低颗粒物在绝缘子表面的碰撞系数和碰撞质量,提高了防污能力,为极端恶劣环境下绝缘子选型提供了参考。

A new type of insulator for catenary cantilever is designed to solve the problem of large area pollution flashover over Lanzhou-Xinjiang high speed railway in the salt lake wind area of Dabancheng. According to the complex electromagnetic field theory and computational fluid dynamics theory, we developed a wind tunnel contaminated simulation model of equal proportion insulator based on the electric field, flow field, particle trace field, and the multi-physical field of interaction between fluid and particle single-phase coupling by using the COMSOL Multiphysics. Taking collision coefficient and distribution coefficient as characterization parameters, we analyzed the contamination characteristics of insulator under different air flow angles. The results show that the collision coefficient of the insulator surface increases with the increase of particle size, at the same particle size, the distribution coefficient of the sheds surface conforms to the normal "γ" distribution, and the distribution coefficient of stick and end fittings conforms to the inverted "γ" distribution when the air flow angle changes from 0°to ±45°. A new type of insulator with booster sheds is installed at the turning point of electric field strength, which can effectively reduce the collision coefficient and collision mass on the insulator surface, improve the anti-pollution ability, and provide a reference for insulator selection in extreme harsh environments.