An MPPT method using phasor particle swarm optimization for PV-based generation system under varying irradiance conditions

Abstract

The dependency of photovoltaic (PV) systems-based generation systems on constantly varying temperatures and incident sunlight affect the non-linear behaviour of PV panels. Therefore, tracking the maximum power output of the PV panels for efficient utilization becomes a challenge, resulting in power losses and the creation of intense heating spots in the shaded areas of the PV modules when the PV modules receive varying degrees of insolation, that is, under partial shading conditions (PSCs). The inclusion of bypass diodes in parallel to each PV module mitigates this problem to an extent but leads to the formation of several peaks in the P-V characteristics. As a result, maximum power point tracking (MPPT) to deliver maximum power at the load becomes a limitation for conventional optimization algorithms as they are normally based on hill climbing algorithm and get stuck at local maxima of the P-V curve. Therefore, metaheuristic algorithms are used thereby eliminating the possibility of getting trapped at the local optima. However, particle swarm optimization (PSO) suffers from delayed convergence, more iterations to reach the optimal point, and random parameter selection. Hence, this study employs an improved version of PSO called Phasor-PSO (P-PSO) in an MPPT controller. The proposed algorithm is parameter-less which results in reduced computational complexity and thus provides quick decision in achieving the maximum power point (MPP). The hardware-in-loop real-time analysis demonstrates the supremacy of P-PSO over PSO in faster convergence, higher efficiency, and reduced power losses during tracking under various PSCs. The P-PSO based MPPT method will find application in grid connected and stand-alone solar PV system with better efficiency of power transfer.