Abstract: A bipolar high-voltage network for an aircraft or spacecraft. The network includes at least one DC-DC converter having two unipolar input connections and two bipolar output connections as well as a reference potential connection, at least two fuel cell stacks which are coupled in series between the two unipolar input connections, and at least two discharge diodes, each connected in parallel with the output connections of one of the at least two fuel cell stacks. The DC-DC converter is operable selectively in a step-up converter mode of operation or a step-down converter mode of operation, as a function of an input voltage between the unipolar input connections.

Abstract: A high-voltage DC voltage unit with a first DC voltage apparatus providing a first high-voltage DC voltage between a first output connection and a second output connection of the DC voltage apparatus or can be fed with a first high-voltage DC voltage. A second DC voltage apparatus provides a second high-voltage DC voltage or can be fed with a second high-voltage DC voltage. A first DC voltage connection is coupled with the first output connection of the first DC voltage apparatus. A second DC voltage connection is coupled with the second output connection of the second DC voltage apparatus. A reference potential connection is coupled with the second output connection of the first DC voltage apparatus, with the first output connection of the second DC voltage apparatus and with an earth potential, the first and second high-voltage DC voltages realising a bipolar power supply.