Study On Mechanism Of Extinguishing Characteristics Of Arc Under Detonation Airflow

With the rapid development of China’s economy,the power grid has developed in the direction of large capacity and high voltage.The lightning strike is the first killer that affects the stable and safe operation of the power grid.The trip accident caused by lightning strikes will cause major safety hazards and economic losses.The lightning protection problem remains a worldwide problem.In recent years,the"drainage-type"lightning protection mode has received extensive attention,but the problem that the common parallel gap can not actively extinguish the arc still exists.Based on the research on the mechanism of the common parallel gap,this paper propose a new type of lightning protection gap device for detonating airflow arc extinguishing.The paper study the physical properties of the arc,including the volt-ampere characteristics of the arc,the potential gradient,temperature,diameter,and plasma flow,and also analy’ze the dynamic equilibrium process of the arc.Establish a system of equations describing the arc plasma under static conditions,and further propose a dynamic model of the arc under the vertical blow of the detonation airflow.Analyze Briefly the detonation reaction,give the calculation formula of detonation reaction parameters,select the dynamite of the detonation airflow arc extinguishing device and carry out the calculation.Use the FLUENT software to simulate the coupling effect of arc plasma and detonation airflow in the semi-closed arc extinguishing chamber of the device,a cloud picture of the temperature field distribution in the arc extinguishing chamber is obtained.Finally,the lightning impulse discharge test and the power frequency current arc extinguishing test were carried out.It can be seen that the detonation airflow can strongly suppress the development of the arc,and the arc is extinguished 4.2 ms under the action of the detonation airflow,and no reignition occurs.According to the actual operation of the arc-extinguishing device on the transmission line,it is found that the installation of the arc-extinguishing device can effectively avoid the lightning trip accident,and the arc-extinguishing device has a high promotion value.