自膨胀气流作用下灭弧防雷装置截断电弧仿真分析与试验研究

Simulation Analysis and Experimental Study on the Truncated Arc of an Are-extinguishing Lightning Protection Device Under the Action of Self-expanding Stream

为了解决配网线路的雷击问题,提高电力系统的防雷性能,利用＂气吹灭弧＂的方法,研制了一种能够抑制工频建弧过程的自膨胀气流灭弧防雷装置。研究了电弧路径控制、电弧突变拐点、电弧弧柱能量分段、自膨胀气流形成与灭弧机理,建立了自膨胀气流耦合工频续流电弧的数学模型,运用流体力学软件FLUENT对管道内自膨胀气流截断电弧的微观过程进行了模拟仿真,还进行了该防雷装置截断电弧试验,并借助高速摄像机捕捉了该防雷装置截断电弧的详细情况。结果表明：自膨胀气流灭弧防雷装置内部的特殊空间结构可以改变电弧发展路径,迫使电弧弧柱形成多个断点,延长后续工频电弧的暂态发展时间;自膨胀灭弧气流能在0.7 ms时间内完全熄灭电弧并抑制重燃;灭弧防雷装置内的建弧过程与灭弧过程几乎同时进行。工频续流电弧在暂态发展初期就将受到自膨胀灭弧气流的深度抑制,在电弧还未发展成熟且能量较小时会被自膨胀气流熄灭。

In order to solve the problem of distribution line lightning, improve the lightning performance of electric power system, we developed a kind of self-expanding stream of arc-extinguishing lightning protection device, which has a high inhibiting effect on frequency arc. The arc path control, arc mutation inflection point, arc column energy segmentation,and the formation mechanism of self-expanding stream were studied, and a mathematical model of self-expanding stream coupling power frequency arc was founded. The micro process of the self expansive airflow truncated arc in the pipeline was simulated by using the fluid mechanics software FLUENT. Moreover, experiments on arc-extinguishing lightning protection device were conducted, and the detailed process of arc extinguishing were recorded by using high-speed cameras. The results show that the special space structure of the self-expanding stream of are-extinguishing lightning protection device can change the arc development path, force the arc column to form multiple breakpoints, and extend the transient development time of the subsequent power frequency arc. Self-expanding arc extinguishing stream can completely extinguish the arc within 0.7 ms and inhibit re-combustion. The arcing process and arc extinguishing process are almost simultaneous in the arc-extinguishing lightning protection device. The power frequency current arc in the initial stage of transient development will be subject to suppression of airflow and extinction.