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.