Improved variable step size PO MPPT algorithm for PV systems

摘要

Algorithms for the maximum power point tracking MPP (Maximum Power Point), seek to maximize the delivered power of a photovoltaic panel. The Perturb and Observe (P&O) algorithm is the more used due to simplicity, however it is not the most efficient due to the perturbation step is fixed, at higher the size step fastest the MPP will be reached, but there would be a high steady state error; if the size step is low there would be less steady state error, but the MPP tracking became slow. Other well know method is the algorithm of Conductance Incremental (IC), in this method the step depends of the power variation versus the voltage. The variable step for P&O is more efficient for short atmospheric variations with less oscillations in the tracking and the variable step for CI is more efficient for big atmospheric variations with a fast MPP tracking. In this paper the 2 methods are combine to reduce oscillations and for a fast tracking for big and short irradiance variations.