SiC-based High Efficiency Bidirectional Battery Converter for Smart PV Residential Systems

Smart PV inverters are essential components of future grids. Beside conventional functionalities they can communicate with the grid, supports the grid with reactive power and with active power from internal battery storage. To maximize internal consumption, a high efficiency bidirectional DC-DC converter for the battery storage is necessary, as energy will be processed twice. Realisation of the battery converter with silicon carbide (SiC) semiconductors offers many advantages compared to Silicon (Si), included higher power density and higher efficiency. In this paper the design of a simple high efficiency 3kW hard switching bidirectional converter based on normally-on SiC JFET is presented, 98.5% maximum efficiency has been obtained with the prototype and a comparison with SiC MOSFet 1st generation is performed.