Abstract
In this paper the problem of obtaining a reduced order model is considered for an interconnected high order system which is composed of several subsystems.
For such systems retaining the internal structure of the original system in a reduced order model is quite important in the engineering view point.
The most desirable solution to the problem would be, of course, to derive an algorithm for constructing a reduced order model under a single criterion, but unfortunately such an approach is not found yet. In stead, here we proceed to approximate each subsystems by reduced order models and combine the results.
In this case there happen the following questions.
1. Does the reduced order model obtained as above preserve the stability property under the assumption that the original system is stable? If not always, under what conditions?
2. How does the reduced order model approximate the input output characteristics of the original system?
This paper answers these questions.
