DC distribution for industrial systems: opportunities and challenges

This paper investigates the opportunities and challenges associated with adopting a DC distribution scheme for industrial power systems. A prototype DC distribution system has been simulated to investigate the issues. One of the issues focused is the interaction between power converters that are used to convert AC to DC and DC to AC. Another challenging issue investigated is the system grounding. These issues become challenging mainly due to the neutral voltage shift associated with the power converters. The paper shows that converter interactions can be minimized with proper filtering and control on the converters. The paper also proposes a grounding scheme and shows that this scheme provides an effective solution by keeping the neutral voltages low under normal conditions and by limiting the fault currents during fault conditions. With these features, DC distribution provides very reliable and high-quality power.