Adaptive nonlinear control of a distributed collector solar field

This paper is concerned with an application of nonlinear adaptive techniques to temperature control in a distributed collector solar field. In the approach followed, the partial differential equation describing the field is approximated by a lumped parameter bi-linear model, whose states are the temperature values along the field. By using feedback exact linearisation together with a Lyapunov´s approach, an adaptive controller is designed. This paper improves on previous work by using a better approximated model which takes into account that, in the field considered, temperature measures are only made at the input and at the output and not along the pipe. The design based on the improved simplified model allows faster convergence of parameter estimate and improved transient responde. The advantages of the new algorithm proposed are illustrated by means of simulations performed in a detailed physical model of the plant.