Stability analysis and model order reduction of coupled systems
In this paper we discuss the stability and model order reduction of coupled linear time-invariant descriptor systems. Sufficient conditions for the asymptotic stability of a closed-loop system are given. We present a model reduction approach for coupled systems based on reducing the order of the subsystems and coupling the reduced-order models through the same interconnection relations as for the original system. Such an approach allows us to obtain error bounds for the reduced-order closed-loop system in terms of the errors in the reduced-order subsystems. Model reduction of coupled systems with unstable or improper subsystems is also considered. Numerical examples are given.
stability coupled systems model reduction error bounds balanced truncation coprime factorization