Optimal power point tracking for stand-alone PV system using particle swarm optimization

A particle swarm optimization (PSO) technique is used to identify the optimal power point of a photovoltaic module used in a stand-alone PV system as a battery charger. The PSO algorithm searches the maximum power point of the PV module by determining the array voltage at maximum point (VMPP). The tracked variable is used as a reference value (set point) to an ON/OFF controller with a tolerance band which controls the operation of a dc boost chopper such that the PV module is forced to operate at the optimal power point. According to the obtained results of the proposed system, the tracking efficiency is not less than 98 % with a convergence time of 14 ms. Compared with the well known Perturb and Observe tracking method, the proposed system is accurate and reliable.