Optimal control applied to distributed solar collector fields with partial radiation

This paper describes and assesses two strategies to control distributed solar collector fields, especially during days with partial radiation due to the passage of clouds. The main objective of these control strategies is to maximize the electrical power generated during different situations in which different parts of the solar field receive different degrees of solar radiation. Simulations were carried out using two connected models, one for the solar field (taking into account all of its loops), that includes the passage of clouds, and another one for the power cycle. The solar field simulated is a pilot plant, in which it is assumed that all the loops have the same characteristics; and the nominal power range of the Rankine cycle is 800-2330 kW. Finally, the improvement in electrical power achieved by both strategies is compared with a typical control strategy that tries to keep constant the outlet oil temperature of the field. This improvement varies between 4% for clear days and 5.7% for cloudy days.