本文首先阐明:在模拟电路故障诊断的元件参数求解法中,引进适当的辅助变量有利于降低诊断方程的非线性。注意到文中所导出的这类仅二阶的非线性诊断方程,其Jacobi矩阵具有规则结构,从而给出一个基于QR分解的分块求解算法。最后以文献[5]中的一个视频放大器为例进行比较,结果表明本文的诊断方程及算法效果优异。 In this paper, firstly, it is clarified that the introduction of appropriate auxiliary variables in the component parameter solution of the analog circuit fault diagnosis is helpful to reduce the nonlinearity of the diagnostic equation. We note that the second-order nonlinear diagnostic equations of this type have a regular structure and give a block-solving algorithm based on QR decomposition. Finally, a video amplifier in [5] is taken as an example to compare the results. The results show that the diagnostic equation and algorithm in this paper are effective.