Abstract:

We propose a new method for solving semi-physical simulation models using a mixed symbolic and numeric approach. In order to meet the real-time requirement of semi-physical simulations, implicit discretization formulae representing the numerical integration algorithm are inserted into the DAEs symbolically at compile stage. Then nonlinear equations will appear in the augmented equation system and all these nonlinear equations should be solved together at each integration step. In order to meet the fine granularity required for solving the models in real-time, tearing algebraic loop is introduced. After that the dimensions of nonlinear equation blocks can be reduced as the time complexity of calculating nonlinear equations increases exponentially with the growth of dimensions. Finally, an example is given to show that the proposed method is not only easy to implement but also efficient.

Key words: semi-physical simulation;discrete DAEs;tearing algebraic loops;real-time integration