An Improved Global Perturbation Observation Algorithm for Partially Shaded Photovoltaic Arrays

Abstract

This paper introduces an improved global perturbation observation (IGP&O) algorithm for maximum power point tracking (MPPT) of photovoltaic (PV) arrays under partial shading conditions. The algorithm is divided into two stages. In the first stage, the algorithm uses the working point of the traditional MPPT mobile PV to make the ratio of the output voltage and current of the PV equal to the set load value. In the second stage, the output point is moved to the maximum power point (MPP) by the IGP&O algorithm. The proposed algorithm is modeled and simulated using MATLAB/Simulink. The simulation results in different cases show that compared with the traditional MPPT algorithm, the average tracking accuracy of the IGP&O algorithm is more than 98.5%, which has the advantage of jumping out of the local extreme point. The power fluctuation of the algorithm is between 0.001W-2.698 W, which has the advantage of small output power fluctuation. Compared with the intelligent optimization algorithm with an average tracking time of 0.14s-0.79s, the average tracking time of the IGP&O algorithm is only 0.005s-0.06s, which has a speed advantage.

Keywords

• Maximum power point tracking (MPPT)
• partial shading
• perturbation observation method