An Improved P&O Based MPPT for PV Systems with Reduced Steady-State Oscillation

Abstract

This paper proposes a perturb and observe (P&O) maximum power point tracking (MPPT) algorithm for photovoltaic (PV) systems. P&O is a simple technique that comes with serious problems, steady-state oscillation, and deviation from the maximum power point (MPP). This algorithm uses variable step size to decrease the convergence time, and it uses the average value of the last three duty cycle to find MPP fast and accurately. In addition, the probability of deviation has been reduced using the direction of the current when the irradiance changes. The irradiance change identifier, steady-state determiner, duty cycle selector, step size alternator, and boundary condition imposer are the extramodules attached to the structure of the original P&O algorithm to change the step size. This algorithm has been tested along with different types of P&O and INC algorithms in MATLAB software and practical experiments using a boost switching converter. The irradiance pattern used in the simulation includes step and slop, increasing and decreasing patterns, and the proposed algorithm obtained an overall efficiency of 98.54%.