Keywords: photovoltaic arrays, photovoltaics, maximum power point tracking, global MPPT, partial shading, GMPPT, particle swarm optimisation, PSO, solar irradiation, solar energy, solar power, PV arrays
Global maximum power point tracking for partially shaded PV arrays using particle swarm optimisation
This paper introduces a global maximum power point tracking (GMPPT) method for a group of photovoltaic modules connected in series and operating under different levels of solar irradiation using particle swarm optimisation technique. Partially shaded PV modules produce several local maxima power points, which makes the tracking of the global maximum power a difficult task. Most of traditional tracking methods fail to work properly under these mismatched conditions. The proposed scheme tracks the global point by finding the optimum value of the PVs current which maximises the total power extracted from the PVs. The system is studied with different types of loads (resistive, inductive and dynamic load). The obtained results confirm that the method is accurate and fast. The minimum tracking efficiency is 95%. Moreover, the convergence time is around 12 ms. Compared with other MPPT techniques, some methods such as perturb and observe method failed due to trapping in minimum local point. Others such as two-stages perturb and observe method requires measurement of PVs temperature and solar irradiance for successful operation.