Automatic structure analysis of large scale differential algebraic systems

This paper presents a new framework for the analysis of the structural properties of the automatically generated mathematical models. Earlier mathematical analysis based on structural calculus was presented by Pantelides (1988), and Unger et al. (1995). These approaches have been shown to produce inconsistent results even for constant coefficient linear DAE systems, Chowdhly et. al (1999), and Gunther et al. (2000). Our proposed method extends the purely structural approach to include both numerical and symbolic information. The structural analysis is augmented to account for the effects of linear terms in the mathematical system rigorously. The proposed method renders a more precise picture of the structure of a DAE system when compared to the purely structural approaches of Pantelides and Unger. In some cases it avoids incorrect index identification due to cancellation of linear terms