Advanced LVDC Electrical Power Architectures and Microgrids: A Step toward a New Generation of Power Distribution Networks

Current trends indicate that worldwide electricity distribution networks are experiencing a transformation towards direct-current (DC) at both generation and consumption level. This tendency is powered by the outburst of various electronic loads and, at the same time, with the struggle to meet the high set goals for share of renewable energy sources (RESs) in satisfying total demand. RESs operate either natively at DC or have a DC link in the heart of their power electronic interface, whereas the end point connection of electronic loads, batteries and fuel cells is exclusively DC. Therefore, merging these devices into dedicated DC distribution architectures through corresponding DC-DC converters arises as an attractive option not only in terms of enhancing efficiency due to reduction of conversion steps, but also for having power quality independence from the utility mains. These kinds of systems generally provide improved reliability in comparison to their alternating current (AC) counterparts since the number of active elements in DC-DC power electronic devices is smaller than in DC-AC converters. Besides that, control design in DC systems is significantly simpler since there are no reactive and harmonic power flows or problems with synchronization.