Recent Results in Solving Index-2 Differential-Algebraic Equations in Circuit Simulation

In electric circuit simulation the charge oriented modi ed nodal analysis may lead to highly nonlinear DAEs with low smoothness properties. They may have index 2 but they do not belong to the class of Hessenberg form systems that are well understood. In the present paper, on the background of a detailed analysis of the resulting structure, it is shown that charge oriented modi ed nodal analysis yields the same index as the classical modi ed nodal analysis. Moreover, for index 2 DAEs in the charge oriented case, a further careful analysis with respect to solvability, linearization and numerical integration is given.