Small-signal modeling of the Boost-Buck for single-phase grid connected photovoltaic systems

In the last few decades, the traditional electrical power grid has undergone by a transformation process in which the decentralization of generation sources seems to playa fundamental role. In this context, the growing presence of solar photovoltaic sources has opened space for the development of more efficient inverters, in particular, the topologies of transformerless inverters and microinverters. Thus, in this paper we will propose the small-signal analysis of a Boost-Buck converter connected to an unfolding circuit for grid-tied single phase applications powered by a photovoltaic arrays. According to the principle operation, the circuit configuration and mathematical modeling will be presented considering the properties of the average state-space model of the converter. Finally, analyzes are performed on the impact of parasitic elements based on the mathematical model, as well as results of simulations of the inverter dynamics will be presented.