. Hybrid Control Results

Using the hybrid model descriptions of the plant, different MPC control approaches can be applied, as those commented on in Chap. 6, Sect. 6.8.4. As an example, some of the results obtained using a hierarchical scheme [411] can be seen in Figs. 7.34 and 7.35. Figure 7.34 shows the operating modes throughout the day and the solar irradiance. It can be seen that the Hybrid MPC system decides the appropriate op­erating mode. Figure 7.35 shows the inlet and outlet temperatures at the generator. Notice that the oscillations observed are due to the on-off gas heater, the behavior is smooth when the solar field produces enough energy.

7.3.3 Summary

Different control strategies have been applied to the air conditioning plant and as an example, a robust controller based on the Иж mixed sensitivity problem for the con­trol of a solar refrigeration plant has been designed. The resulting method is simple
and it is limited to shaping only one parameter for each of the outputs considered. A basic feedback structure and a more complex one including a disturbance feed­forward compensation loop have been designed. These controllers have been tested using the real plant, concluding that the performance achieved justifies the use of such a kind of regulator.