Robust control approach for photovoltaic conversion system

This paper proposes an algorithm of maximum power point tracking (MPPT) applied for photovoltaic (PV) power generation systems based on boost DC-DC converter and robust control tools using Linear Matrix Inequalities (LMI) technique. In this study, the nonlinearities and the parametric uncertainties of the system are taking into account. The strategy of this algorithm consists on the generation of a voltage reference which corresponds to maximum power points using a fuzzy algorithm. This is obtained from direct measurements of solar irradiation and temperature of the PV-panel. After this; the paper proposes a robust control based on fuzzy Takagi-Sugeno (T-S) model to follow this reference and consequently force the operating point of a panel to track the maximum power point (MPP). Two objectives are covered by this control: (i) to guarantee H∞ performances and minimize the influence of disturbances on the output; (ii) to ensure stability against parametric variations of the system. These two objectives have been achieved by the resolution of LMIs system. The performances of the proposed approach are ensured in simulation, using real profiles of irradiance and temperature measured on photovoltaic platform.