A Space Vector Modulation Technique for H8 Transformerless Three-Phase Photovoltaic Inverter

The use of a transformerless three-phase inverter in grid-connected photovoltaic (PV) systems presents a cost-effective and compact solution. However, the absence of galvanic isolation can lead to the circulation of leakage currents, which are caused by parasitic capacitances in the PV panels. To address this issue, several topologies are proposed and combined with modulation techniques to reduce the leakage current. This paper proposes a space vector modulation technique applied to a transformerless three-phase inverter topology to further reduce the leakage current by assigning a new space vector, where the common-mode voltage will have a smaller variation in certain regions. Simulation results are presented in order to demonstrate the performance of the new modulation technique.