Modified Perturb and Observe (P&O) with checking algorithm under various solar irradiation

This paper proposes a modified maximum power point tracking (MPPT) technique for photovoltaic (PV) system using an improved Perturb and Observe (P&O) with a checking algorithm. The main advantage of this method is its simplicity and accuracy of the algorithm such that it can even be computed accurately using a low cost microcontroller. The basic idea of this modified P&O is adding a checking algorithm into a modified P&O MPPT. This checking algorithm functions to determine the global maximum power by comparing all existed peak points first, before the modified P&O algorithm takes place to identify the voltage at MPP (VMPP), which is needed to calculate the duty cycle for the boost converter. A simulation using MATLAB/Simulink under partial shading condition has been done to test the effectiveness of the algorithm. The simulation results are satisfactory and show that the improved technique is able to track the PV maximum power during partial shading condition with 100% of tracking efficiency and produce zero ripple at the load side.