Common Mode Current Reduction in High Power DC Microgrids Using Steering Diodes

Diode “oring” (or steering) is often used to provide battery backup power for many consumer products. For higher power dc microgrids such as those found on commercial or military maritime vessels, auctioneering diodes may be used for no-break power from multisource paths to vital loads. This paper addresses the following two issues: (a) the observed uneven distribution of negative bus current when employing only positive auctioneering diodes with multiple loads on the same circuit, and (b) the observed double load voltage discovered during one possible double ground fault scenario. An arrangement with anti-parallel diodes on the negative rail provides both balanced rail impedances and a path for fault current.