Temperature Control in Solar Furnaces Using Nonlinear PID-based Control Approaches

Nowadays, the efficient use of renewable energies is of great importance both socially and economically. This research focusses on capturing energy from the Sun and studying the modelling and control of the SF60 solar furnace at the Plataforma Solar de Almería (PSA) in Spain. The main goal is to regulate the temperature profile of a silicon carbide (SiC) sample. To do this, two main stages of analysis are established. The first one involves modelling the system, where the nonlinear and linear models are designed and calibrated. The next part is the control of the plant, where control strategies based on both linear and nonlinear models are developed, taking into account the speed of response, steady-state specifications, and process constraints. The main control schemes applied have been PI control (with anti-windup mechanism), feedforward control, and PI-based feedback linearisation control, which have been properly tuned using different methodologies. One of the major contributions of this work has been the validation of the developed control schemes in the real installation, after simulation using the nonlinear model. Finally, the advantages and disadvantages of each controller are discussed.