Dynamic global power extraction of partially shaded PV system using a hybrid MPSO-PID with anti-windup strategy

Abstract

Particle Swarm Optimizer (PSO) has three main drawbacks in case of partially shaded photovoltaic systems. First, it converges slowly to the global peak (GP). Second, because PSO is a time invariant, it cannot adhere to a dynamic GP in the presence of various temporal shading patterns and instead, sticks to the first GP. Third, it exhibits high oscillations around GP. To overcome these shortcomings, this paper proposes a novel hybrid modified PSO-PID (MPSO-PID) with anti-windup strategy based maximum power point tracking. The anti-windup strategy aims to guarantee the robustness of the PID controller and eliminate the PID windup outcome. Two anti-windup structures were applied to PID namely: anti-windup using back calculation and anti-windup using conditional integration. For validation purpose, the hybrid MPSO-PID with anti-windup has been compared with conventional PSO and three modified PSO versions namely: PSO with random numbers eliminated (PSO-RNE), PSO with linearly varying parameters (PSO-LVP), and PSO with fixed maximum iterations (PSO-FMI). The obtained simulation and experimental results revealed that the proposed MPSO-PID with anti-windup overcome the previous shortcomings providing outperformance to track dynamic GP with a less convergence time and small oscillations around GP compared to other algorithms. The proposed MPSO-PID technique has a minimum average response time; 0.026 s; to catch the GP under various shading patterns compared to the other PSO versions; CPSO, PSO-LVP, PSO-RNE, and PSO-FMI; where the average response time are 0.026 s, 0.531s, 0.446 s, 0.763 s, and 0.494 s respectively. Finally, the results proved the robustness and effectiveness of PID design for enhancing both the PSO and PV system performance.