In experiment 1, Figs. 4.20 and 4.21 show experimental results obtained with MMAC in the DCSF considered. Figure 4.20 depicts the time evolution of the main variables of the control loop, namely the manipulated variable (fluid flow in (l/s), multiplied by 10 for graphical convenience), the reference, with a decreasing step followed by a sequence of three increasing steps, and the outlet fluid flow, that closely follows the reference. Figure4.21 shows the index of the active local controller as a function of time. This index changes not only after reference changes, but also due to radiation changes that may happen during periods in which the reference is kept constant.
Fig. 4.20 Controlling a DCSF with SMMAC: experiment 1. Reference, output temperature and manipulated variable (°C) [fluid flow in (l/s) multiplied by 10]. Time in (h)
From the analysis of Fig. 4.20 it is concluded that there is a small overshoot and a settling time of about 6 min, that is considered to be very good in this plant.