Analysis of improved PSO and perturb & observe global MPPT algorithm for PV array under partial shading condition

Abstract

The power-voltage (P-V) characteristic curve of photovoltaic (PV) system have nonlinear and multiple peaks characteristics under partial shading condition. This paper proposes a novel maximum power point tracking (MPPT) control method for PV system based on an improved particle swarm optimization (PSO) algorithm and variable step perturb and observe (P&O) method. Firstly, the grouping idea of shuffled frog leaping algorithm (SFLA) is introduced into the basic PSO algorithm, ensuring the differences among particles and the searching of global extremum. And then, the variable step P&O method is used to track the global maximum power point (GMPP) accurately with the change of environment. Finally, the superiority of the proposed method over the traditional PSO algorithm in terms of tracking speed and steady-state oscillations is highlighted by simulation and experimental results under partial shading condition.