I. Introduction
Photovoltaic (PV) systems represent one of the most important solutions to face the renewable energy demand of the next years [1], [2], [3]. The connection of PV arrays to the utility grid is implemented by means of grid-connected PV systems (GPVSs). Important features of GPVSs are power factor correction (PFC) and maximum power point tracking (MPPT). In order to carry out such important features, single stage GPVSs (SS-GPVSs) and double stage GPVSs (DS-GPVSs) are usually employed [4], [5], [6], [7], [8], [9].