Modulation Strategy for Leakage Current Reduction in Three-Phase Transformerless Split-Source Inverters for Photovoltaic Applications

Abstract

In view of the expansion of Photovoltaic (PV) generation systems, new technologies have been developed to ensure a suitable operation. PV systems with low input voltages usually employ an input boost converter and an output grid-connected inverter. The recently proposed Split Source Inverter (SSI) provides the power conversion which aggregates boost capability with low switch count. On the other hand, conventional modulation strategies applied to the grid-connected SSI can result in large leakage currents. It is important to mention that the leakage currents must be limited in order to prevent hazard issues. This paper proposes a Space Vector Modulation (SVM) strategy for transformerless grid-connected systems for the SSI in order to minimize the leakage currents. In addition, a comparison among different SV strategies is presented to demonstrate the benefits of the proposed technique.