简单电容电路最小点燃电压曲线的数值化研究

Research on Digitization of the Minimum Ignition Voltage Curve of Simple Capacitive Circuit

为建立本质安全电路的非爆炸性评价系统奠定基础,应用Matlab中Cftool工具箱,以插值法对简单电容电路的最小点燃曲线进行拟合,实现了最小点燃曲线的数值化。将最小点燃曲线分为两部分,以不同的固定步长读取电压值及电容量,通过将读取的数据以对数来表示,使得在普通坐标下,就可在较大范围内显示电容和最小点燃电压之间的关系;基于自然边界,采用三次样条插值法求得所选定各点之间的电压值和电容量,使得所读取数据点的拟合曲线更接近最小点燃曲线;利用Matlab的程序设计,实现了对插值结果的数值化查询。实例及结果验证了所提出数值化方法的正确性与可行性。

To lay the foundation for establishing a non-explosive evaluation system of the intrinsic safety circuits, minimum ignition voltage curve of simple capacitor circuit was fitted with interpolation method by Cftool toolbox in Matlab. It made the digitization of minimum ignition curve come true. The minimum ignition curve was divided into two parts, in which the voltage and capacitance were got with different fixed-step values. Then we can show the relationship in a wide range between capacitance and minimum ignition voltage by logarithmic transformation of data we got in normal coordinates. The voltage and capacitance between points selected were obtained with the cubic spline interpolation method based on natural boundaries, which made that the curve fitted is more closer to minimum ignition curve. The numerical queries of the results were realized by the design of Matlab function. Examples and results validated the correctness and feasibility of the method proposed.