考虑非弹性随机碰撞与SF_6/N_2混合气体影响的直流GIL球形金属微粒运动行为研究

Motion Analysis of Spherical Conducting Particle in DC GIL Considering the Influence of Inelastic Random Collisions and SF_6/N_2 Gaseous Mixture

针对直流气体绝缘金属封闭输电线路(gas insulated metal enclosed transmission line,GIL)金属微粒污染物问题,研究球形金属微粒在其中的运动行为,采用贴合实际情境的同轴圆柱电极结构,建立直流GIL内球形金属微粒运动模型:纳入SF6/N2混合气体动力学参数,利用流体力学理论分析微粒运动过程中混合气体阻力的影响;同时考虑金属表面粗糙度影响,利用弹性力学中的碰撞理论分析金属微粒与导体及外壳的非弹性随机碰撞,实验结果验证了模型计算的可靠性。利用模型对微粒运动轨迹进行仿真分析,并根据微粒运动的分布情况提出微粒活跃度的概念,研究表明:微粒在导体与外壳间的谐振频率与微粒半径、SF6占比、绝缘气压呈负相关;微粒活跃度与随机反射角、电压幅值呈正相关,而随着微粒半径变化存在极大值。

To solve the problem of metal-particles pollution in DC gas insulated metal enclosed transmission line（GIL）, in a more realistic situation of coaxial cylindrical electrodes, the motion analysis of spherical metal particle was made in DC GIL structure. Based on the theory of fluid mechanics and considering the SF6/N2 mixtures parameters, analysis of the flow resistance in the process of particle movement Was proposed. Based on the collision theory of elastic mechanics and considering the random effects caused by roughness of metal surface, analysis of the collides between the particle and the conductor or the shell was also proposed. On the basis of these two factors, the motion model of spherical metal particle in DC GIL was established and the experimental results validate the accuracy of the model. Furthermore, the motion trails of the particle were simulated based on the concept of particle vitality proposed according to the distribution of particle movement. It is observed that the resonant frequency of the particle between the conductor and the shell decreases with particle radius, SF6 proportion and insulating air pressure increasing; the particle vitality increases with the random angle of reflection and the applied voltage increasing, but there is a maximum in the relation between the vitality and the particle radius.