电极类型对封闭容器内部短路燃弧特性及压力升的影响

开关柜内部短路燃弧故障时有发生,其短时间释放巨大能量引起隔室内部压力迅速上升,严重威胁设备、建筑物以及工作人员的安全。由于实际开关柜内部电弧试验周期长、耗费大,模拟封闭容器内部短路燃弧试验成为研究该问题的主要手段。利用L-C振荡回路开展了封闭容器内部棒–棒、板–板间隙短路燃弧试验,分析了不同电极类型对封闭容器内部短路燃弧特性和压力升(相对压强)的影响,结果表明:封闭容器中弧压受压强、气流和电极类型等因素影响,数值与开放环境差异较大。棒–棒和板–板间隙燃弧对应的电弧电位梯度范围分别为18.8～23.8 V/cm和15.9～19.6 V/cm,其中板–板间隙的弧压数据波动较为剧烈,分散性更大,且数值小于棒–棒间隙。相同间隙距离和电弧能量下,板–板间隙短路燃弧引起的压力升大于棒–棒间隙。

Influence of Electrode Types on Arcing Characteristics and Pressure Rise Due to Internal Short-circuit Arcing in a Closed Container

Internal short-circuit arcing faults in the switchgear happen occasionally, and huge energy released by the arc in a short time makes the pressure rise rapidly in the compartment, bringing a great threat to the safety of equipment,building and operation personnel. The arc tests in actual switchgear are time-consuming and highly costing, so the internal short-circuit arcing tests in a simulated closed container become a main way to study this problem. In this paper, the short-circuit arcing tests of rod-rod and plane-plane gaps in a closed container are carried out by the LC oscillation circuit, and the influence of electrode types on the arcing characteristics and pressure rise(relative pressure) in a closed container is analyzed. Results show that, the arc voltage is related to the factors, such as pressure rise, airflow, electrode type and so on. The value of arc voltage is different from the open environment. The ranges of the arc voltage gradient for rod-rod and plane-plane gaps are 18.8~23.8 V/cm and 15.9~19.6 V/cm, respectively. For plane-plane gap, the arc voltage has big fluctuation and showing a large degree of randomness,which is smaller than the rod-rod gap. Under the same gap distance and arc energy, the pressure rise caused by the arcing of plane-plane gap is greater than the rod-rod gap.