SS诊断策略在非线性电路中的应用研究

Researches on SS Diagnosis Method's Application in Non-linear Circuits

研究模拟电路故障诊断问题,非线性一直是制约模拟电路故障诊断技术发展的关键问题之一。传统故障诊断中,灵敏度序列(Sensitivity Sequence,SS)诊断策略集中在线性电路的故障诊断,但是对于非线性电路的故障诊断,仍缺乏相关研究。为此对非线性电路中应用SS诊断策略进行了研究,从分析非线性元件参数特性出发,引入分段线性迭代的方法构建元件的线性模型,采用戴维宁和诺顿定理进行模型的等效替换;分段进行测前仿真,构造故障字典。理论推导以及试验结果证明,采用分段线性迭代方法构建非线性元件的分析模型,避免了在诊断过程中求解繁复的非线性代数方程或非线性微分方程,为在非线性电路应用SS诊断策略提供了有效的分析模型;借助工作域以及对带有容差的一般情况的分析和研究,进一步完善了非线性电路中SS诊断策略的应用;所提的方法,能够快速准确地提取非线性电路故障的灵敏度特征,提高故障识别和隔离的效率。

Nonlinear is one of the important problems that restricts the developments of analog circuit＇s fault diagnosis.Dislike the achievements in the diagnosis of linear circuit,the corresponding researches of Sensitivity Sequence（SS） diagnosis method in non-linear circuits are still deficiency.Aimed to solve the aforementioned problem,a strategy of applying the SS diagnosis method into the non-linear circuits is presented.The non-linear parameter curve is separated by PWL（Piece Wise linear） models and the non-linear devices are replaced by the Thevenin＇s or Norton＇s equivalent circuits.Secondly,the fault dictionary is formed by stimulations before test.The theory analysis and experimental results show that,compared with the non-linear algebra and differential equation,the PWL model is more compact and efficient.The analysis of operation domain and tolerance consummates the SS diagnosis method＇s application in non-linear circuits.The method can sensitize the fault characteristics and improve the diagnosis efficiency.