Safety considerations for the operation of bipolar DC-grids

DC microgrids can offer many advantages for an installation in commercial applications like data centers or in private homes. In this paper, future expansion of such grids towards a bipolar architecture (e.g. ±380 VDC) is evaluated. The focus lies on various fault situations, their effects on the grid and possible solutions to maintain grid safety. For this purpose, a laboratory scale bipolar test grid is set up and subjected to ground faults, loss of neutral and load shedding.