Transformerless topologies for grid-connected single-phase photovoltaic inverters

In order to improve the efficiency and reduce the cost of a photovoltaic system, the use of transformerless photovoltaic inverters is an alternative of increasing interest. However, this topology needs to be studied in detail, as it presents some problems related to the galvanic connection between the grid and the photovoltaic generator (e.g. efficiency degradation and safety problems). In this paper, a review of grid-connected single-phase photovoltaic inverters based on transformerless topologies has been carried out. On the one hand, some alternatives based on classical topologies have been presented. On the other hand, alternatives based on multi-level inverter topologies have been studied, showing up that no leakage current is generated in comparison to classical topologies. (C) 2011 Elsevier Ltd. All rights reserved.