Hybrid supervisory control of a solar air conditioning plant

The control of solar plants is challenging for several reasons, one of which is that the solar irradiation representing the main energy source cannot be manipulated and is subject to large disturbances due to changes of the weather conditions. For the solar air conditioning plant considered in this work, additional difficulties arise from the presence of discretely switched valves and pumps and autonomous switchings of the continuous dynamics which make it a hybrid system. The main control goal for this process is to minimize the consumption of auxiliary energy while ensuring a safe and robust operation even in the face of large disturbances. Since the existing hybrid models of the plant do not represent the process dynamics accurately, this paper presents a robust supervisory control scheme that was designed based on a thorough investigation of the energetic aspects of the solar plant. The application of the control scheme to a real solar plant illustrates the robustness and efficiency of the approach.