Audi Ag

Thomas Hackner

Rolf Naumann

Josef Winkler

Christian Glück

Viktor Kell

Bernhard Stock

Markus Fischer

Karsten Barth

Daniel Renner

Stefan Pfaller

The disclosure relates to a method for controlling an electrical system of an electrically drivable motor vehicle, wherein the electrical system includes at least one lead battery and at least one lithium battery. Initially, a lower and a first upper threshold value for a state of charge of the lithium battery are determined. Then, a second upper threshold value which is higher than the first upper threshold value is determined. During the driving operation of the motor vehicle, a state of charge of the lithium battery is set between a lower and a second upper threshold value. When the motor vehicle is switched off, the state of charge of the lithium battery is determined. If the state of charge of the lithium battery is higher than the first upper threshold value, the state of charge of the lithium battery is lowered to the first upper threshold value.

Method for controlling an electrical system of an electrically drivable motor vehicle having a plurality of batteries, and electrical system of an electrically drivable motor vehicle having a plurality of batteries

A method for providing a power supply for at least one electrically heatable catalyst of a motor vehicle situated in an exhaust gas tract, wherein the motor vehicle comprises a first battery, by means of which a first voltage Uis generated, and a second battery, by way of which a second voltage Uis generated, wherein the at least one catalyst during a start phase immediately following the start of an internal combustion engine of the motor vehicle is supplied by a power Pprovided by the first battery such that the voltage Uof the first battery is imposed on the at least one catalyst, wherein the at least one catalyst is additionally supplied during the start phase by a power Pprovided by the second battery such that the voltage Uof the second battery is transformed by a DC converter to the value of the voltage Uwhich is imposed on the at least one catalyst.

Method for providing a power supply for at least one electrically heatable catalyst of a motor vehicle situated in an exhaust gas tract, and a motor vehicle comprising at least one electrically heatable catalyst situated in an exhaust gas tract of the motor vehicle

An embodiment relates to a method for predicting a voltage dip in a vehicle electrical system before a planned start of a load in a motor vehicle. The embodiment operates to ascertain a value of supply current expected to be required after the start of the load. An electrical voltage source and an energy store connected in parallel to a voltage source via the vehicle electrical system provide the supply current for operating the load. The energy store blocks a charge current into the energy store or blocks a discharge current out of the energy store based on a vehicle electrical system voltage of the vehicle electrical system being greater than a maximum value. Based on an instantaneous value of the vehicle electrical system voltage, the embodiment further ascertains a proportion of the supply current that the voltage source generates as a source current without the energy store until the vehicle electrical system voltage has fallen to the maximum value.

Prediction of a voltage dip in a motor vehicle

A method is disclosed for operating an electrical system of a motor vehicle, said electrical system comprising a first power source for providing an operating voltage for at least one partial onboard network of the electrical system and at least a second power source, wherein an electrically conductive connection of the first power source to the electrical system is monitored for an intentional interruption and, in the event of a detected intentional interruption of the electrically conductive connection, the at least one second power source of the electrical system is separated therefrom or deactivated. A motor vehicle with an onboard electrical system and a control device, for execution of the method, are also disclosed.

Method for operating an electrical system of a motor vehicle, and motor vehicle

A method for determining a performance information, including a capacity information, of a battery of a motor vehicle on-board power network connected to a DC converter is disclosed. The DC converter is configured to impress at least one AC current with at least one predetermined frequency into the on-board power network. The capacity information is derived from at least one first electrical parameter at an output of the DC converter to the on-board power network and from at least one second electrical parameter that describes a reaction of the battery to the impressed AC current. A motor vehicle configured to perform the method is also disclosed.

Method for determining performance information of a battery of a motor vehicle on-board power system that is connected to a direct current converter, and motor vehicle

A process to check a connection between a battery () supplying a low-voltage network () of a motor vehicle (), the voltage of which is less than the voltage of a high-voltage network () of the motor vehicle (), and the low-voltage network (); wherein a DC voltage converter (), which is configured for exchanging electrical power between the high-voltage network () and the low-voltage network (), connects the high-voltage network () to the low-voltage network (); wherein a DC voltage converter () modulates the output voltage into the low-voltage network at a modulation frequency; wherein the current hereby applied and the voltage hereby applied are measured by the battery (), and a resistance value is determined and evaluated with respect to at least one connection criterion, according to which a connection fault is determined when at least one connection criterion is not fulfilled.

Growing community of inventors

Greding, Germany

Thomas Hackner