Hybrid switch use for light load efficiency improvement of a power inverter for stand-alone residential renewable energy system

Abstract

In stand-alone residential renewable energy systems (such as solar and/or fuel cell powered), the power inverter used for DC-AC transformation will operate at light loads, where its efficiency is lower, most of the time during a day. Thus, improving the inverter efficiency at light loads will result in more efficient use of renewable energy sources. In this study, the use of a parallel IGBT-MOSFET switch combination and its unique control is analyzed for efficiency improvement at light load conditions. Experimental results are provided for a half bridge inverter with and without hybrid switch. It is shown that the light load efficiency can be improved with the proposed hybrid switch use. As the use of renewable energy sources is on the rise, even the slightest increase in the inverter efficiency will mean large energy savings overall.