Symmetric Flying-capacitor Boost Converter for Medium-voltage Photovoltaic Applications

Inhalt:
Photovoltaic (PV) energy is seen today as an essential energy source to achieve a carbon-neutral society. With that purpose, great pressure exists in terms of energy costs (€/MWh). In utility-scale PV systems, the increase of system voltages beyond low-voltage standards are being studied. In this paper, a novel medium-voltage DC/DC boost converter is proposed, capable of operating with 3 kV PV strings. The investigated topology is the 5-level symmetric flying-capacitor equipped with 1.2 kV/16 mOmega SiC MOSFETs. Experimental switching characterization results are provided and the main design aspects of the 80 kW SiC-based prototype are discussed. The estimated peak and European efficiencies are 99.5 and 99.33%, respectively.