Bidirectional Leakage Current-Less Modulation of H6 Inverter with Reduced Switching Loss

Abstract

Transformerless photovoltaic (PV) inverters are more widely adopted due to their high efficiency, low cost, light weight, etc. H6 transformerless PV inverters can suppress leakage current while do not have the bidirectional capability for a photovoltaic-energy storage system (PV-ES). Therefore, this paper proposes a bidirectional leakage current-less modulation strategy for H6 inverter topology, by improving the modulation strategy in the rectifier stage, only two switches are turned on at high frequency in rectifier mode. The leakage current in inverter and rectifier mode can be suppressed while switching loss can also be reduced. Finally, to validate the proposed modulation strategy, a simulation is also built and tested. The simulation results validate the theoretical analysis.