Some Case Studies in Approximate Models in Multivariable Process Control

摘要

Methods for choosing approximate engineering plant models are given. Simple controllers corresponding to each model are given. Using the given model and controller forms, the stability and performance of the approximate control system are decided. A more general measure of model/real plant mismatch is derived implying a less conservative necessary condition for including integral control action. In one of the examples presented, problems occur due to the bad condition of the steady state matrix. It is shown that even in this case the stability condition has a simple form.