爆炸气流强压下灭弧防雷间隙截断电弧自熄机理与试验研究

发布时间：2018-03-16 21:13

本文选题：爆炸气流　切入点：灭弧防雷间隙　出处：《广西大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着我国电力网架的不断铺设和特高压线路的高速发展,架空线路的防雷方式变得更加重要。在我国雷电活动遍及各个省市,由雷击闪络造成的绝缘子损坏、线路断线和停电事故是非常普遍的,在线路跳闸事故中占据较大的比重。针对“堵塞型”防雷方式的效果不佳问题,提出了“疏导型”和爆炸气流气吹电弧相结合的防雷方法。本文从交流电弧的伏安特性、弧柱电位梯度、温度和电弧直径等参数特性出发,研究电弧发展的参数变化。建立电弧自熄的离子模型,从微观角度分析爆炸气流对电弧的破坏作用,进一步分析爆炸气流对介质恢复强度的影响。根据链式电弧模型对交流电弧进行受力分析,通过爆炸气流强压下气体压力计算推导出电弧运动特性与爆炸气流压力的关系,并结合电弧自熄时间的仿真流程得出电弧的自熄时间。其次,建立交流电弧三维MHD模型、爆炸区域质点电弧数学模型和爆炸气流强压下气体的能量变化模型,利用ANSYS14.0有限元软件对爆炸气流和交流电弧进行耦合,对爆炸气流截断电弧过程和气流压力分布进行仿真,模拟爆炸气流动作后电弧自熄的动态过程。最后,搭建试验平台进行爆炸气流强压下截断电弧的自熄试验,在有效绝缘配合下对多次试验数据进行数理统计得到电弧的自熄时间,并得出爆炸气流速度与电弧自熄时间的关系。进一步分析灭弧防雷间隙的实际挂网运行情况,在雷击频度高的线路上运行效果良好,一致说明雷击时爆炸气流强压下交流电弧能够自熄。
[Abstract]:With the continuous laying of power grid in China and the rapid development of UHV lines, the lightning protection mode of overhead lines becomes more important. In China, lightning activities are widespread in all provinces and cities, and the insulators are damaged by lightning flashover. Line breakage and blackout accidents are very common and account for a large proportion of line tripping accidents. In this paper, a lightning protection method combining "grooming type" and explosion gas blowing arc is proposed. The characteristics of voltage and ampere characteristics, arc column potential gradient, temperature and arc diameter of AC arc are studied in this paper. The parameter change of arc development is studied. The ion model of arc self-extinguishing is established, and the destructive effect of explosion flow on arc is analyzed from the microscopic point of view. According to the chain arc model, the stress of AC arc is analyzed, and the relation between arc motion characteristic and explosion flow pressure is deduced by calculating the gas pressure under the strong pressure of explosion airflow. Combined with the simulation flow of arc self-extinguishing time, the self-extinguishing time of arc is obtained. Secondly, the three-dimensional MHD model of AC arc, the mathematical model of particle arc in explosion region and the energy change model of gas under strong pressure of explosion flow are established. The ANSYS14.0 finite element software is used to couple the explosion flow with the AC arc. The arc truncation process and the pressure distribution of the explosion flow are simulated to simulate the dynamic process of the arc self-extinguishing after the explosion flow moves. The self-extinguishing test of the cut off arc under the strong pressure of explosion flow was carried out on a test platform, and the self-extinguishing time of the arc was obtained by mathematical statistics of the test data under the effective insulation cooperation. The relationship between the velocity of explosion airflow and the time of arc self-extinguishing is obtained. Further analysis is made on the actual operation of the gap between arc extinguishing and lightning protection, and the running effect on the lines with high lightning strike frequency is good. The results show that the AC arc can be extinguished under the strong pressure of the explosion flow during the lightning strike.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM863

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