A Comparison of Three Optimizing Control Strategies Applied to PV/T Systems

Photovoltaic/thermal (PV/T) systems are combined photovoltaic and thermal systems. These systems are suitable for hose applications where there is lack of space and both types of energy are needed. Both electric and thermal power obtained from the PV/T systems, can be optimized through proper control strategies. In this work, three optimizing control strategies are compared. The first strategy uses a model to calculate the gradient of the generated power, the second is based on the perturbation-averaging extremum seeking approach, and the third is based on a time-varying extremum seeking control. Lyapunov theory is used in all the cases for convergence analysis. Simulation results show that all three strategies reach their objectives. The main differences were in terms of the implementation complexity, signals waveforms and the convergence times. Experimental evaluation is part of the current research.