本质安全电路电弧放电点燃特性检测系统研究

以往对本质安全电路电弧放电点燃特性非爆炸方法的研究大多是针对本质安全电路设计,主要是通过对不同电路类型调节电路参数,使之达到规定的安全系数.根据电路的结构不同电弧放电的模型也不同,但是无论其放电特性如何,都可以按单次电弧放电能量来考察其点燃特性.本测试系统不考虑电路性质与电路参数,通过放电能量来判断电路的点燃特性.非爆炸方法测定电弧点燃可燃性气体特性的方法,就是使用波形记录设备记录电弧放电的电压和电流波形,对每一次放电的波形进行分析,计算放电能量,从而判定电弧是否可以点燃可燃性气体.该方法具有设备简单、造价低廉、不需要爆炸气槽、监测迅速的特点,使本安产品可以在出厂时得到有效的检测.     

Analysis of low energy arc discharge characteristics based on dynamic V-A characteristics model

Low energy arc discharge characteristics was analyzed based on dynamic V-A characteristics model. It draws conclusions that discharge time relates to the source voltage and the product of inductance and stable current, discharge time will increase when the source voltage increases; current reduce rate is in inverse proportion to the value of inductance; arc resistance when the arc occurs is the ratio of minimum arcing voltage to stable current. It also gains the expressions of arc resistance and arc power, arc resistance and arc power both increase as the source voltage increases and decrease as the value of inductance increases. Conclusions above mentioned are helpful to design intrinsically safe circuits.