MPPT techniques for a photovoltaic pumping system

A study of some MPPT algorithms and type (central or distributed) for an off-grid photovoltaic installation is presented. First, the efficiency of using MPPT algorithms in a specific application (water pumping) has been proved. Then, some widely used MPPT algorithms (Table Look-up Neuro-fuzzy, Incremental Conductance and Perturb and Observe) are compared, independently on the application. Their performances are evaluated using measured data from the target area, and compared in similar conditions, thanks to simulations. Since the P&O algorithm is easy to implement, and it shows a fast dynamic performance, although the non-linearity of the photovoltaic panel´ model, it is selected to track the MPP and is successfully tested on a detailed model of a Buck converter, using PowerSim. Then, the power efficiency comparison between the central and distributed MPPT is discussed.