系统辨识作为一种常用的"黑箱"系统建模方法,为评估测试系统在瞬态测量中的动态特性提供了重要依据。通过理论分析和仿真计算阐述了在全频带范围内建立宽带电磁脉冲(EMP)测试系统动态数学模型的局限性,在此基础上给出了一种连续域的分步辨识建模方法,可用于解决测试系统在全频带范围内的数学建模问题。仿真分析结果表明,分步辨识建模方法有效融合了测试系统的低频和高频动态校准数据,得到的一体化连续域辨识模型能反映测试系统从低频至高频全频带范围内的动态特性。实验测试结果也验证了此方法的可行性。
As a kind of commonly used black-box system modeling method,system identification plays an important role in getting and assessing the dynamic characteristic of a measurement system in the transient test experiment.The electromagnetic pulse(EMP) including LEMP,NEMP and ESD EMP often has frequency components from DC to GHz.On the basis of analyzing the calibration method in time-domain,the input source selection,and the experiment data processing method,the problems of identification modeling within a broadband range effectively of the EMP measurement system were discussed,and a step identification modeling method was proposed.Simulation results indicate that,by using low-frequency and high-frequency calibration data in time-domain,a model to represent the whole characteristics in a wideband of the real measurement system can be established by the method.The feasibility of this step identification modeling method is also verified by the experiment test.