研究电感分断放电电弧电阻模型是建立电感电路非爆炸本安性能评价的基础.运用IEC安全火花试验装置对电感分断电弧放电特性进行试验研究,深入分析电弧电阻随放电时间的变化规律,并采用非线性回归的方法得出分断电弧放电时间与电感和初始电流之间的函数关系式.考虑安全火花试验装置钨丝和镉盘电极结构特点,建立了一种极间电弧放电区域的物理模型,并推断出二维泊松方程的边界条件.基于此,利用分离变量法求解泊松方程,推导出电弧电阻的数学表达式,得出了电感分断电弧放电电压和电流的关系表达式.仿真分析及实验结果证明了理论分析及所提出电弧电阻数学模型的准确性和可行性.
Inductor-Disconnected-Discharged (IDD) arc resistance model established is foundation of the evaluation of the non-explosive intrinsically safe performance for inductive circuit. The IDD characteristics were studied through test, based on the IEC safety spark test apparatus. The change laws of the discharge resistance with duration were deeply analyzed. By using non-linear regression method,the function relationship was obtained between the IDD time, inductance and initial current. Considering the tungsten and cadmium electrode structures of the IEC spark-test apparatus, a physical model of the inter-electrode arc discharge was established,and the boundary conditions of two-dimension Poisson' s equation were inferred. Based on this, the algorithm of variable separation was applied to solve the Poisson' s equation. Then, the mathematical expression of arc resistance was deduced. The relational expression between the arc discharge voltage and current of the IDD discharge were obtained for the low voltage circuits. The simulation and experiment results show that the theoretical analysis and proposed model are valid and feasible.