Abstract: A supply device for the electrical supply of at least one consumer has a primary current system in which there is a fuel cell device, a secondary current system in which there is a battery which has an operating voltage range limited at the top by a maximum voltage and at the bottom by a minimum voltage and which has an operating current strength range for supplying current to the at least one consumer, and a frost-starting element, which is provided in the primary current system and is designed to bring about heating of the fuel cell device. An open-circuit voltage of the fuel cell device corresponds at most to the maximum voltage of the battery.

Abstract: A multi-phase converter for an energy system, as is used in fuel cell vehicles, and methods for operating the multi-phase converter, are described herein.

Abstract: An onboard electrical system for a motor vehicle is provided having a primary power supply network and a secondary power supply network electrically connected to the primary power supply network via a DC-DC converter, wherein the primary power supply network and the secondary power supply network are connected to one another via a blocking diode of the DC-DC converter and the blocking diode has a forward direction thereof oriented from the primary power supply network toward the secondary power supply network, and wherein an insulation monitoring device having a measuring resistor is associated with the secondary power supply network for determining an insulation fault. It is provided that an additional resistor is connected in parallel with the blocking diode for bridging thereof, such that an insulation fault common to the primary power supply network and the secondary power supply network can be determined by the insulation monitoring device.

Abstract: An electrical energy system containing fuel-cells and a method for operating an electrical energy system for a motor vehicle are disclosed. The electrical energy system includes, for example: at least one fuel-cell; at least one HV battery; a diode arranged between the at least one fuel-cell and the at least one HV battery, which diode allows current flow only in a direction from the at least one fuel-cell to the at least one HV battery; a switching element configured to reversibly disconnect or close a circuit between the at least one fuel-cell and the at least one HV battery; a control unit configured to control the switching element; and an inductor arranged between the at least one fuel-cell and the at least one HV battery and connected in series with the switching element.

Abstract: The disclosure relates to a drive device for a motor vehicle, with a primary power network and a secondary power network, wherein a fuel-cell device is provided in the primary power network, and a battery is provided in the secondary power network, and a drive unit of the drive device is electrically connected to the secondary power network, and wherein the battery provides, within an operating voltage range delimited downwards by a minimum voltage and upwards by a maximum voltage, electric current for proper operation of at least one electrical consumer over an operating current range delimited downwards by a minimum amperage and delimited upwards by a maximum amperage. It is provided in this respect that an open-circuit voltage of the fuel-cell device correspond at most to the maximum voltage, and that the fuel-cell voltage provided by the fuel-cell device across the operating current range be higher than the minimum voltage.

Abstract: The invention relates to a method for operating a fuel cell arrangement which has a fuel cell for providing electrical energy in an electric circuit that has a circuit which is electrically connected to the fuel cell via a DC-DC converter, and a battery. It is provided that in at least one mode of operation of the fuel cell arrangement, following a start-up of the fuel cell, the battery is electrically disconnected from the circuit, and the DC-DC converter is operated in non-switched mode in order to supply at least one electrical consumer in the circuit with electric current provided by the fuel cell. The invention further relates to a fuel cell arrangement.

Abstract: The invention relates to a method for operating a fuel cell arrangement which has a fuel cell for providing electrical energy in a circuit, at least one fuel cell auxiliary unit, the circuit electrically connected to the fuel cell via a DC-DC converter, and a battery. In this case, it is provided that, in order to place the fuel cell into operation, the battery be electrically connected to the circuit and the fuel cell auxiliary unit be operated with electrical energy drawn from the battery, wherein the battery is electrically disconnected from the circuit, and the DC-DC converter is operated in non-clocked mode in at least one operating mode of the fuel cell arrangement after placement into operation. The invention further relates to a fuel cell arrangement.