Integration of low level controller constraints in supervisory control of buildings

Abstract

Model Predictive Control (MPC) has been widely used and proved efficient in the control of building installations. It is particularly efficient in the supervisory control of equipment since it can integrate economic, social and environmental dimensions in the computation of the control input. In practice, these equipment possess their own devoted and integrated controllers, which include power saturations and operating modes. Therefore, equipment's inputs cannot be directly controlled by supervisory controllers. This paper aims at analysing to what extent MPC controllers can incorporate existing integrated controllers without introducing extra complexity to their strategies. A Proportional-Integral (PI) controller, with an anti-windup mechanism, has been implemented as the so-called integrated controller. A proposed MPC strategy is discussed. Despite the hybrid functioning of the PI controller, it maintains the simplicity of the problem solving. Furthermore, a comparison between the performances of a benchmark MPC controller (which would drive directly an equipment possessing no integrated controller) and the developed MPC controller is presented. For this study, an office building is targeted and the heating issue has been addressed.