Abstract:
We consider the problem of stabilizing multi-evaporator vapor-compression cycle (ME-VCC) systems using decentralized controllers. ME-VCC systems, sometimes termed variabl...Show MoreMetadata
Abstract:
We consider the problem of stabilizing multi-evaporator vapor-compression cycle (ME-VCC) systems using decentralized controllers. ME-VCC systems, sometimes termed variable-refrigerant-flow systems, are prevalent in large buildings that maintain independent cooled spaces with a single heat rejection unit. We exploit the time-scale separation characteristic of ME-VCC systems and analyze the faster mass flow dynamics and their stability characteristics independently of the slower thermal dynamics in the system. An electrical circuit analogy is used to obtain a linearized state-space representation of the mass flow dynamics for two common architectures of ME-VCC systems. Using concepts from decentralized control theory, we provide conditions under which local static feedback controllers stabilize the overall closed-loop system with robustness to uncertainties in the coupling between subsystems. Our analysis characterizes the beneficial impact that discharge pressure regulating (DPR) valves have on the decentralized controller gains.
Date of Conference: 10-13 December 2012
Date Added to IEEE Xplore: 04 February 2013
ISBN Information: