Bi-level Optimal Control Strategy for Heating, Ventilation, and Air Conditioning System with Collaborative Consideration of Air Quality and Thermal Comfort

As the main energy consuming part of intelligent buildings, heating, ventilation and air conditioning (HVAC) system has great significance to fulfil the flexible trade-off between their energy consumption cost and user comfort. However, when the above two factors are considered in parallel, the coupling terms of the system optimization model and the difficulty in solving increase. The learning-based control strategy is convenient in model construction, but the energy-saving effect is average. According to the above challenges, a bi-level optimal control strategy for HVAC system with collaborative consideration of air quality and thermal comfort is proposed. Firstly, the coupling relationship between temperature and air quality in each area is accurately portrayed based on the thermal dynamic model of the RC equivalent circuit and the internal physical structure of the building. Secondly, the operation strategy of the HVAC system is optimized with the objectives of the minimum system energy cost and maximum user comfort. A bi-level optimal approach is developed to solve this complex coupling problem, with the upper level optimizing the supply air volume and the lower level optimizing the ventilation rate. The approximating error from model linearization is corrected by using the rolling optimization method. Finally, the results of the proposed strategy with different comfort coefficients are analyzed in the summer cooling scenario and compared with other control strategies. The consequences show that the method can balance the economy and user comfort. © 2024 Automation of Electric Power Systems Press. All rights reserved.