A branch and bound approach for building cooling supply control with hybrid model predictive control

Abstract

In this article a branch and bound approach for hybrid model predictive control of a building cooling supply is presented. This specific algorithm is the core part of a mixed-integer model predictive controller (MI-MPC) for energy efficient management of a cooling supply incorporating active storage connected to a switching chiller. The MI-MPC is applied to the model of the cooling system of a large office building in Salzburg, Austria. An efficient modelling strategy combines data-driven black-box identification and analytically derived white-box modelling for the purpose of predictive control. The validation of the resulting linear and hybrid energy supply models is done by an open loop simulation. Simulation results of the proposed control structure show excellent performance compared to the implemented conventional control strategy resulting in an increased usage of at least 50% of renewable energy sources, a cut in energy costs of about 50%, and an optimised operation of the active storage while accurately delivering the prescribed cooling power trajectory. The approach is thus promising for industrial application.