Control and optimal management of a heliostat field for solar power tower systems

The competitiveness of Concentrated Solar Power (CSP) plants over conventional ones still has to be improved. For CSP systems based on Central Receivers (CRS), one of the challenges to face is the optimal management of the aim points of the heliostats which form the collector field. The flux distribution that the field projects on the receiver must be carefully controlled to get an adequate form and to avoid dangerous flux peaks that might damage the receiver. Phenomena such as cloud transients can result in pronounced temperature gradients that reduce the life expectancy of receivers. Therefore, it is necessary to develop a control system which ensures that the critical parameters of the receiver (e.g., temperatures, solar radiation, pressure, mass flow) are always within the allowed range. This work presents an automatic control system connected to an optimization method based on a genetic algorithm which theoretically configures the field to obtain any desired flux distribution. It is a heuristic feedback controller that minimizes the error between the flux distribution theoretically computed and that obtained over time. The control logic tries to reduce the effect of perturbations as well as modeling and optimization errors that might have affected the genetic optimizer when computing the initial operating state.