The increasing demand for electrical power, along with the decreasing stock of traditional energy sources, has caused a growing interest towards microgeneration from renewable power sources. In particular, photovoltaic energy (PV) has witnessed an increasing attention and the scientific community has concentrated its efforts in order to develop innovative solutions for the integration of PV systems into the existing distribution grid. In this thesis PV converters for grid-connected systems without galvanic insulation were studied. A particular solution of a multilevel-based converter was employed in a PV application and its behavior was thoroughly analyzed. Extensive simulations and experimental results confirmed the feasibility and the good performance of the proposed solution.