An Enhanced P&O MPPT Algorithm With Concise Search Area for Grid-Tied PV Systems

Abstract

Due to improved efficiency of solar photovoltaic (PV) systems, this article proposes a modified perturb and observe (MPO) maximum power point tracking (MPPT) algorithm. The MPO algorithm in question adopts a tracking approach that divides the power-voltage curve into four operational regions based on the estimated open-circuit voltage. Additionally, this algorithm enhances the maximum power point (MPP) tracking method by reducing unnecessary step-size calculations, focusing only on a 10% Section of the power-voltage curve that contains the MPP. Consequently, the two regions located far from the MPP, below 90% of the power-voltage range, utilize a large fixed step-size to ensure swift tracking speed. Furthermore, in the regions close to the MPP, the remaining areas employ a similar tracking strategy as the adaptive P&O algorithm, aiming to achieve minimal steady-state oscillations around the optimal MPP. The performance of the proposed MPO algorithm is demonstrated by validating it against sinusoidal, ramp irradiance, and one-day (10 hr.) irradiance profiles using MATLAB/SIMULINK. The simulation results confirm that the proposed algorithm outperforms recently published techniques in terms of convergence speed, achieving the shortest time of 15 ms, and slightly higher tracking efficiency of the PV system under uniform irradiation, reaching 99.8%.

Keywords

• PV system
• large-scale PV array
• grid-tied systems
• MPPT
• P&O
• boost converter