Dynamic modeling of multiple-zone vapor compression cycles using variable order representations

This paper presents a new modeling approach for describing the dynamics of multiple-zone vapor compression cycles. It is demonstrated that such systems may undergo a class of structural variations that can change the system order. To facilitate analysis and control design for variable order dynamics a new modeling approach based on a subsystem decomposition is developed. This procedure exploits the underlying physical structure of the system to achieve a systematic way of representing order variations. It is shown that this result, while conceptually simplifying the modeling problem, introduces a new control problem associated with algebraically constrained subsystems. An observer design case study is used to demonstrate some potential pitfalls in analysis of variable order systems