Abstract: In multi-domain modeling, the problem of initial consistency must be settled to solve differential algebraic equations (DAEs). Structural analysis is capable of verifying the initial consistency, solving some initial values and determining the degree of freedom, but not capable of affirming the variables that need to be initialized. If improper selection is made for the initiation variables, it will become low efficient and even fail to solve and simulate the model. After analyzing the initial consistency of DAEs, a strategy based on DM decomposition is proposed for selecting the initialization variables. The method decomposes the system into two parts with the use of DM decomposition after the system is structurally analyzed. By analyzing the reachability of under constraint part, the initialization variables can be affirmed. This method is efficient to affirm the initialization variables and avoids wrong selections.

Key words: multi-domain modeling, differential algebraic equations (DAEs), initial consistency, maximum matching, DM decomposition