碳电极交流电弧伏安特性的实验研究

Experimental Research on Voltage-Current Characteristics of Carbon AC Arc

交流电弧伏安特性是电器开关能够可靠熄弧的关键所在。本文首先借助电弧发生装置完成了空气介质中碳材料交流电弧电压和电弧电流的测试,进而应用小波分解与重构方法获得了电弧伏安特性的数学描述。并以能量平衡原理阐释了交流电弧零休与燃弧期间的物理过程。针对实验中零休期间电弧电流为非零恒定值的现象,提出并证明了零休期间电弧可等效为恒定电容的结论。最后实验研究了电源电压和电极开距参数对起弧电流和零休时间的影响。所得结论可应用于电器开关熄弧过程中等效电路模型及暂态响应分析。

The voltage-current（V-I） characteristics of the AC arc is very critical for the extinguishment of arc which exists within the electrical apparatus. The AC arc voltage and current of carbon electrodes in the air are measured by using arc generating device, and the mathematical description of arc V-I characteristics are obtained with the help of the wavelet decomposition and reconstruction method. In addition, the physical process of the arc approaching ＇zero＇ duration and burning period are interpreted by the principle of energy balance. The arc current is a nonzero constant value is observed when it changing direction, thus the equivalent constant capacitor is presented and proved explicitly. Finally, the effect of supply voltage and electrode gap on minimal arc current and approaching ＇zero＇ duration are analyzed. The conclusions draw in this paper could be applied for the transient analysis of the equivalent circuit model with arcing phenomena.