State observer for water-based hybrid PV/T system with unknown input
Résumé
This paper deals with the observer design problem for bilinear photovoltaic-thermal (PV/T) thermal model to estimate its states. The objective is to construct an observer subjected to an unknown input. This study proposes an improvement in the design compared to the work in the literature on the application of a state observer with unknown input for photovoltaic-thermal systems where x^ is estimated by knowing T˙wi. A Lyapunov approach is used to ensure stability and a Linear Matrix Inequality (LMI) is solved simultaneously in order to find a positive definite symmetric matrix subject to linear equality constraint. Necessary and sufficient conditions for the existence of such approach are given. A design procedure is summarized and the proposed technique is finally illustrated through simulations. Results indicate that the state estimation error converges to zero for all the states, thus displaying effectiveness of the presented scheme.