Abstract: A safety device for a DC grid includes a voltage measuring device between a potential line and a reference potential line, and a protective circuit for reducing an electric shock caused by Y-capacitors of the electric DC grid. The protective circuit includes a circuit breaker between the respective potential line and the reference potential line. A plurality of tripping criteria are predefined and the first circuit breaker and/or the second circuit breaker can be actuated so as to close exclusively in the event of all predefined tripping criteria being met as determined by the first voltage measuring device and/or by the second voltage measuring device.

Abstract: A direct current converter includes a plurality of direct current converter modules having electrical input voltages and output voltages that differ from each other. The plurality of direct current converter modules are electrically connectable to one another to form a plurality of subsystems such that a high-voltage electrical voltage is convertible into different low-voltage electrical voltages. The plurality of direct current converter modules are configured as a shared integrated assembly. At least one of the plurality of subsystems is always active.

Abstract: A component arrangement for an electric high-voltage on-board power supply of a vehicle includes a shared EMC filter, a shared intermediate circuit, a plurality of electrical components, and a shared housing. The shared EMC filter and the shared intermediate circuit are provided for the plurality of electrical components. The plurality of electrical components are disposed in the shared housing together with the shared EMC filter and the shared intermediate circuit. The plurality of electrical components are interconnected in parallel with the shared intermediate circuit and the shared EMC filter and there is otherwise no electrical connection between them.

Abstract: An electrical drive system for a vehicle includes an electrical three-phase machine for driving the vehicle, an electrical energy storage device for electrically supplying the electrical three-phase machine during a driving operation of the vehicle, an inverter of the electrical three-phase machine, which inverter is electrically coupled to the electrical energy storage device. The system also includes a charging connection on the vehicle side for electrically coupling the electrical energy storage device to a vehicle-external charging unit. As a function of the inverter, a charge voltage of the charging connection on the vehicle side can be transformed into a supply voltage for charging the electrical energy storage device.

Abstract: A vehicle electrical system for a motor vehicle includes a high-voltage battery for providing a positive potential and a negative potential and a high voltage load. An insulation monitor monitors insulation resistances to a vehicle ground galvanically isolated from the vehicle electrical system. Between the positive potential and the vehicle ground and between the negative potential and the vehicle ground, a Y capacitor is provided in each case. A voltage center tap between the positive potential and the negative potential, which voltage center tap is present in the vehicle electrical system or in a component of the vehicle electrical system, is connected to the vehicle ground by an ohmic coupling resistor.

Abstract: An electric driving system for a vehicle includes a switching device having first and second switching states. In the first switching state, in which a charging port is directly connected with an electrical energy storage device of the vehicle, the electrical energy storage device is charged with an input voltage applied to the charging port. In the second and third switching states the charging port is connected with the electrical energy storage device via an inverter such that the electrical energy storage device can be charged depending on the inverter.

Abstract: An electric drive system for a vehicle includes first and second three-phase electric machines driving a vehicle axle and an electrical energy store electrically supplying the first and second three-phase electric machines during a driving operation of the vehicle. A first and second inverter of the first and second three-phase electric machines, respectively, are each coupled to the electrical energy store. The system also includes an onboard charging terminal for electrically coupling the electrical energy store to a charging unit external to the vehicle. According to the first and/or second inverter, a charging voltage of the onboard charging terminal is converted into a supply voltage for charging the electrical energy store.

Abstract: An insulation monitor for a high-voltage onboard electrical system of a motor vehicle is provided. A respective Y-capacitor is arranged between the positive potential and the vehicle earth and between the negative potential and the vehicle earth. The insulation monitor has a current or voltage source, a voltmeter for measuring at least one of the potentials, and is configured to apply a negative current by the current source when the potential measured by the voltmeter exceeds a predefined upper value and to apply a positive current by the current source when the potential measured by the voltmeter falls below a predefined lower value. The current thus being limited to a maximum permissible contact current in the case of an insulation fault and it is possible to infer the magnitude of the insulation resistances using the voltage measured by the voltmeter and the recharging current that has been fed in.

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 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 method for charging an energy storage device of a vehicle. A charging process of the energy storage device is carried out with a charging device of the vehicle. In a first phase of the charging process, the energy storage device is charged with a first DC voltage of the charging source in dependence on a charging current of the charging source. A battery voltage of the energy storage device is determined during the charging process and is compared with the charging voltage of the charging source. A voltage transformer is operated in dependence on the comparison. In a second phase of the charging process, the energy storage device is charged with a second DC voltage of the voltage transformer in dependence on a choke current of the voltage transformer.

Abstract: A method for monitoring at least one Y-capacitance of an electrical on-board power supply of a vehicle includes ascertaining a current capacitance value of the at least one Y-capacitance and a current on-board power supply voltage of the electrical on-board power supply. The method further includes determining a currently stored amount of energy in the at least one Y-capacitance depending on the current on-board power supply voltage of the electrical on-board power supply and the current capacitance value of the at least one Y-capacitance of the electrical on-board power supply, comparing the currently stored amount of energy in the at least one Y-capacitance to a predetermined threshold value, and generating a control signal when the predetermined threshold value is exceeded in the comparing.

Abstract: A method for monitoring at least one Y-capacitance of an electrical on-board power supply of a vehicle includes ascertaining a current capacitance value of the at least one Y-capacitance and a current on-board power supply voltage of the electrical on-board power supply. The method further includes determining a currently stored amount of energy in the at least one Y-capacitance depending on the current on-board power supply voltage of the electrical on-board power supply and the current capacitance value of the at least one Y-capacitance of the electrical on-board power supply, comparing the currently stored amount of energy in the at least one Y-capacitance to a predetermined threshold value, and generating a control signal when the predetermined threshold value is exceeded in the comparing.

Abstract: A circuit arrangement of a motor vehicle includes a high-voltage battery for storing electrical energy, an electric machine for driving the motor vehicle, a converter via which high-voltage direct current voltage provided by the high-voltage battery is convertible into high-voltage alternating current voltage for operating the electric machine, and a charging connection for providing electrical energy for charging the high-voltage battery. The converter is a three-stage converter having a first switch unit which is assigned to a first phase of the electric machine. The first switch unit has two switch groups connected in series which each have two insulated-gate bipolar transistors (IGBTs) connected in series, where a connection is disposed between the IGBTs of one of the two switch groups, which connection is electrically connected directly to a line of the charging connection.

Abstract: A protection device for an electric DC grid includes a first protection circuit part including a series circuit consisting of a first discharge resistor and a first protection switch between a positive potential line and a reference potential line and a second protection circuit part including a series circuit consisting of a second discharge resistor and a second protection switch between a negative potential line and the reference potential line. The first and second protection switches can be actuated to close if a first and/or second voltage measuring device ascertains that a specified voltage value has been undershot and/or exceeded or the first and/or second protection switch can be actuated to close in an event of a fault current measured by a fault-current measuring device.

Abstract: An on-board charger for charging a high-voltage battery of a high-voltage on-board electrical system or a low-voltage battery of a low-voltage on-board electrical system includes a first DC converter which has a transformer having a primary side and a secondary side where the high-voltage battery can be supplied with a first DC voltage via a first circuit of the secondary side of the first DC converter. The low-voltage battery can be supplied with a second DC voltage via a second circuit of the secondary side. A control unit activates either the first circuit or the second circuit of the secondary side of the first DC converter. For operating the low-voltage on-board electrical system by the high-voltage battery, the first DC converter is configured such that the first DC converter converts a battery voltage of the high-voltage battery into the second DC voltage in the second circuit of the secondary side.

Abstract: A circuit arrangement of a motor vehicle includes a high-voltage battery for storing electrical energy, an electric machine for driving the motor vehicle, a converter via which high-voltage direct current voltage provided by the high-voltage battery is convertible into high-voltage alternating current voltage for operating the electric machine, and a charging connection for providing electrical energy for charging the high-voltage battery. The converter is a three-stage converter having a first switch unit which is assigned to a first phase of the electric machine. The first switch unit has two switch groups connected in series which each have two insulated-gate bipolar transistors (IGBTs) connected in series, where a connection is disposed between the IGBTs of one of the two switch groups, which connection is electrically connected directly to a line of the charging connection.