Modular Photovoltaic Generation Systems Based on a Dual-Panel MPPT Algorithm

In this paper a modular structure for grid-connected photovoltaic generation systems is presented. The basic generation unit consists in a quasi-parallel connection of two PV panels, with a dedicated buck-boost (or fly-back) PWM converter. The chopper input voltage, i.e., the PV panels' voltage, is regulated according to a novel MPPT algorithm, based on a forced small displacement in the working points of the PV panels. Outputs of the several generation units are parallel connected to the dc-bus of a standard active power filter, linked to the electric network. The grid-inverter regulates the dc-bus voltage to a proper fixed value, injecting the power coming from the units into the mains. Each generation unit works as a stand-alone converter, i.e., signal connections among the units or between each unit and the main active filter are not required.