
7
Simulation Tools
7.1 INTRODUCTION
Mathematical models of dynamic systems are derived with their intended use in mind. For example,
systems with fast internal dynamics driven by inputs that change infrequently (relative to the system
time constants) reside in steady state the majority of the time. Accordingly, the model consists of a
system of coupled, possibly nonlinear, algebraic equations. In this context, a solution (or solutions)
defines an equilibrium state (or states) corresponding to fixed values of the system inputs. When one
or more inputs change, a stable system transitions from one equilibrium state to another and the
dynamics, that is,