Abstract: A vehicle energy transmission circuit is equipped with an insulation fault detection circuit that has a fault current measurement apparatus, a first high-voltage connector, a second high-voltage connector, a ground potential connector, a first measuring resistor, a second measuring resistor and a measuring switch. One of the high-voltage connectors is connected in series with a connecting point via one of the measuring resistors and the measuring switch. The measuring resistor connects the other high-voltage connector directly to the connecting point. The connecting point is connected to the ground potential connector via the fault current measurement apparatus. The fault current measurement apparatus is configured to record a current that flows between the connecting point and the ground potential connector. The fault current measurement apparatus is configured to record this current when the measuring switch is open and closed.

Abstract: The invention relates to a protection device for voltage-limiting elements of a low-voltage line that extends out of a vehicle high-voltage region. A vehicle high-voltage device having a high-voltage region (HV), which is arranged in a housing (G), and having at least one low-voltage line (NL) is described. Said low-voltage line leaves the high-voltage region (HV) through an aperture (D). The high-voltage region is provided in the housing (G). The aperture (D) is provided in an outwardly delimiting housing wall (GW) of the housing (G). The at least one low-voltage line (NL) is connected to a ground potential (M) or to a connection therefor via a voltage-limiting element (V) and a current-limiting element (SG) connected in series with said voltage-limiting element.

Abstract: A high-voltage vehicle on-board electrical system is equipped with a ground potential and a high-voltage potential that is insulated from the ground potential by a two-stage insulation. The two-stage insulation has a first insulation device that insulates the high-voltage potential from a potential island. A second insulation device of the two-stage insulation insulates the potential island from the ground potential. The potential island is connected to the ground potential via a dissipating element. The dissipating element is configured, in the event of an insulation fault in the two-stage insulation, to generate a current that is below a hazard threshold and that is above a sensitivity threshold of an insulation monitor.

Abstract: A monitoring circuit for a high-voltage DC charging apparatus provides for the monitoring circuit to have a first high-voltage busbar and a second high-voltage busbar as well as a reference potential. This is electrically insulated from the high-voltage busbars. The monitoring circuit has a current sensor apparatus which is configured to capture a common-mode current flowing through the high-voltage busbars. The monitoring circuit also has a control device. The current sensor apparatus has a signal-transmitting connection to the control device, and the control device is configured to emit a fault signal if the magnitude of the common-mode current exceeds a limit. Furthermore, a DC voltage charging station, a DC voltage charging cable, a vehicle charging circuit and a method for detecting a fault in a high-voltage DC charging process are described.

Abstract: A method for detecting an insulation fault in a vehicle on-board electrical system having an HV and LV on-board electrical system branches. The LV branch has at least one first LV potential and a second LV potential that differs therefrom and corresponds to a ground potential of the vehicle on-board electrical system. The HV branch has positive HV negative HV potentials. These HV potentials are DC-isolated from the LV branch potentials. An insulation fault between at least one of the HV potentials and the first LV potential is detected by identifying a current flow. The current flow runs through a voltage limiting circuit connected between the ground potential and the first LV potential. This circuit connects the first LV potential, via a plurality of diodes, to a voltage limiting element connected to the ground potential of the vehicle on-board electrical system. A vehicle overvoltage protective circuit is also described.

Abstract: A monitored DC charging method for charging a vehicle rechargeable traction battery by way of a charging voltage source external to the vehicle is provided. The rechargeable traction battery has a nominal voltage of at least 500 V. In a checking step, the method includes detecting whether the charging voltage source has a surge protector which includes a voltage limiting element that is provided between a charging voltage potential and a ground potential of the charging voltage source and is set up to transition to a conductive state from a voltage below the nominal voltage. DC voltage is transmitted from the charging voltage to the rechargeable traction battery when the charging voltage source does not have the surge protector. At least one DC charging mode for transmitting DC voltage from the charging voltage source to the rechargeable traction battery is suppressed when the charging voltage source has the surge protector.

Abstract: A vehicle electrical system is equipped with at least one high-voltage consumer, a DC charging connection a rechargeable battery, a rectifier and a changeover switch. The high-voltage consumer is connected to the rechargeable battery by the changeover switch via a first switching device in a first switching position of the changeover switch and is connected to the rechargeable battery by the changeover switch in a second switching position of the changeover switch via a second switching device, wherein the DC charging connection is connected to the rechargeable battery via the first switching device.

Abstract: A charging and heating circuit is equipped with an AC voltage connection, a DC voltage connection and a rectifier. The rectifier is connected between the AC voltage connection and the DC voltage connection. The charging and heating circuit further includes a heating resistor which is connected to the rectifier and the rectifier is thereby set up to supply the heating resistor with current. Also described is a vehicle electrical system which includes the charging and heating circuit in addition to an accumulator.

Abstract: A method for checking the functionality of a high-voltage protective device for an on-board vehicle electrical system is provided. The protective device has a varistor or a different voltage limiting element. The method provides that the capacitive component of the alternating current impedance of the varistor or the voltage limiting element is detected. The capacitive component is further compared to a rated capacitance value, where the rated capacitance value is characteristic of the capacitance of a functioning varistor or voltage limiting element. A defective state of the varistor or the voltage limiting element is determined when the comparison determines that the capacitive component deviates from the rated capacitance value by more than a predetermined magnitude. Furthermore, a high-voltage protection circuit for a vehicle and a high-voltage on-board vehicle electrical system is provided.

Abstract: A DC vehicle charging circuit is equipped with an input, a converter circuit designed as a boost converter, and an output. A first input potential of the input is connected to a first output potential of the output via the converter circuit. The converter circuit is connected to a second output potential of the output via a connection point. A second input potential of the input is connected to the connection point without semiconductor switches, except for one transistor. The transistor has an inverse diode, the forward direction of which corresponds to the direction of a charging current that flows when energy is transferred from the input to the output.

Abstract: A vehicle electrical system is equipped with a high-voltage zone, a first low-voltage zone extending out of the high-voltage zone, a second low-voltage zone, and a safety device. The safety device connects the first low-voltage zone to the second low-voltage zone. The safety device has a galvanic isolation component or a voltage limiting element.

Abstract: An onboard electrical system is disclosed that includes first, second and third onboard electrical sub-systems for an electric drive unit, electric components and a vehicle battery of a vehicle, respectively. In addition, the system includes a charging terminal, wherein a changeover switch, a first switch element, and a second switch element of the onboard electrical system are physically separated from one another. The charging terminal is galvanically connected to the third onboard electrical sub-system by the first switch element and to the second onboard electrical sub-system by the changeover switch during an electric charging mode of the vehicle battery. The first onboard electrical sub-system is galvanically connected to the third onboard electrical sub-system of the second switch element and to the second onboard electrical sub-system by the changeover switch during a driving mode of the vehicle.

Abstract: A vehicle on-board electrical system is equipped with a DC voltage charging connection, a non-configurable accumulator, a galvanically isolating DC-DC voltage converter, and an electrical drive. The accumulator is connected to a first side of the DC-DC voltage converter via a switchable connection circuit to which a DC voltage charging connection is connected. The accumulator is connected to the electrical drive and a second side of the DC-DC voltage converter via a drive switch. The connection circuit has a direct connection switch that connects the accumulator to the first side of the DC-DC voltage converter in a switchable manner. The DC voltage charging connection is connected to the direct connection switch via a charging connection switch of the connection circuit.

Abstract: A method is disclosed for conducting a pre-charging process of an onboard electrical system of a vehicle and for a charging process of a vehicle battery of the vehicle. The charging process immediately follows the pre-charging process. The vehicle battery is galvanically connected to a first onboard electrical sub-system of the onboard electrical system by a first switch element and a changeover switch and is galvanically separated from a charging path of the onboard electrical system by a second switch element. A line capacitor in the charging path is pre-charged to a first voltage value by a power source electrically connected to the charging path. A capacitor in the first onboard electrical sub-system is pre-charged to a second voltage value by the vehicle battery, wherein the vehicle battery is charged by the power source on the basis of the respective state of charge of the line capacitor and the capacitor.

Abstract: A vehicle on-board electrical system having an AC voltage charging connection, a rechargeable traction battery, which is designed as a high-voltage rechargeable battery, and a power factor correction filter. The power factor correction filter connects the AC voltage charging connection directly to the rechargeable traction battery. The operating voltage range of the rechargeable traction battery is within the output voltage range of the power factor correction filter.

Abstract: A vehicle electrical system is equipped with a DC charging connection, a rechargeable battery, a DC-DC converter and an electric drive. The DC-DC converter has a first side that is connected to a connecting point via a first switching device. The DC-DC converter has a second side to which the electric drive is connected and which is connected via a second switching device and to the connecting point. The connecting point is connected to the rechargeable battery. The DC charging connection is connected to one side of the first switching device that is connected to the first side of the DC-DC converter.

Abstract: A charging voltage converter on a vehicle is equipped with an upstream circuit, which includes at least one working inductor. Furthermore, the converter has a switching unit, which is connected downstream of the upstream circuit. The working inductor connects a first input potential of an input of the voltage converter to the switching unit. A second input potential of the input is connected via a reverse current blocking device of the upstream circuit to the switching unit.

Abstract: A vehicle electrical system is equipped with a DC charging connection, a rechargeable battery, a first DC-DC converter and an electrical drive. The first DC-DC converter has a first side. This is connected to a connecting point via a first switch. The first DC-DC converter has a second side to which the electrical drive is connected. The second side is connected to the rechargeable battery via a second switch and via a connecting point or is connected to the rechargeable battery directly. The vehicle electrical system has a second DC-DC converter. This is connected to one side of the first switch.

Abstract: A vehicle electrical system is equipped with at least one high-voltage consumer, a DC charging connection a rechargeable battery, a rectifier and a changeover switch. The high-voltage consumer is connected to the rechargeable battery by the changeover switch via a first switching device in a first switching position of the changeover switch and is connected to the rechargeable battery by the changeover switch in a second switching position of the changeover switch via a second switching device, wherein the DC charging connection is connected to the rechargeable battery via the first switching device.

Abstract: A charging circuit is equipped with a storage battery terminal, a direct-current terminal and an alternating-current terminal, which is connected to an alternating-current side of a rectifier of the charging circuit. The direct-current side of the rectifier is connected via a changeover switch to a first side of a DC-to-DC converter, wherein the changeover switch connects the first side of the DC-to-DC converter either to the direct-current terminal or to a first potential of the direct-current side of the rectifier. A second potential of the direct-current side of the rectifier is connected to the direct-current terminal via a diode. The reverse direction of the diode points toward the direct-current terminal. A second side of the DC-to-DC converter is connected to the storage battery terminal, to which the direct-current terminal is connected via an isolating switch. A vehicle electrical system having the charging circuit is also described.