On-board electrical system for a motor vehicle and method for operating an on-board electrical system for a motor vehicle

Patent metadata

Field	Value
Publication number	US-2025135951-A1
Application number	US-202318835805-A
Country	US
Kind code	A1
Filing date	Jan 16, 2023
Priority date	Feb 11, 2022
Publication date	May 1, 2025
Grant date	—

Abstract

The disclosure relates to an on-board electrical system for a motor vehicle having a first partial on-board electrical system which has a first on-board electrical system voltage, a second partial on-board electrical system which has a second on-board electrical system voltage, lower than the first on-board electrical system voltage, a first and a second DC/DC converter which are each arranged between the first and the second partial on-board electrical system, and an energy store arranged in the second on-board electrical system. The disclosure also relates to a method for operating such an electrical system.

First claim

1 . An on-board electrical system for a motor vehicle, comprising:
a first partial on-board electrical system having a first on-board electrical system voltage, a second partial on-board electrical system having a second on-board electrical system voltage lower than the first on-board electrical system voltage, a first DC-DC converter and a second DC-DC converter arranged between the first and the second partial on-board electrical system, and an energy store arranged in the second partial on-board electrical system.

2 . The on-board electrical system according to claim 1 , wherein the first partial on-board electrical system further comprises a high-voltage energy store.

3 . The on-board electrical system according to claim 2 , further comprising a control device configured such that,
in a normal operating mode, energy from the first partial on-board electrical system is supplied to the second partial on-board electrical system via the first and second DC-DC converters; and when a failure of one of the first or second DC-DC converter occurs, energy is supplied from the first partial on-board electrical system to the second partial on-board electrical system via a remaining one of the first or second DC-DC converter that has not failed.

4 . The on-board electrical system according to claim 3 , wherein
the second partial on-board electrical system has at least two parallel strands and an electrical component, and the electrical component is connected to the at least two parallel strands.

5 . The on-board electrical system according to claim 4 , wherein each of the at least two parallel strands comprises a distribution unit with a fuse.

6 . The on-board electrical system according to claim 5 , wherein the second partial on-board electrical system has a main distribution unit which is connected to the distribution units of the at least two parallel strands and to the first and second DC-DC converters.

7 . The on-board electrical system according to claim 3 , wherein the main distribution unit of the second partial on-board electrical system has a system for charging or discharging the energy store.

8 . The on-board electrical system according to claim 7 , wherein a ratio of the second on-board electrical system voltage to the first on-board electrical system voltage is in a range of 0.01 to 0.04.

9 . A method for operating an on-board electrical system for a motor vehicle, comprising:
providing an on-board electrical system comprising:
a first partial on-board electrical system having a first on-board electrical system voltage,
a second partial on-board electrical system having a second on-board electrical system voltage lower than the first on-board electrical system voltage,
a first and a second DC-DC converter arranged between the first and the second partial on-board electrical system, and
an energy store arranged in the second partial on-board electrical system,
supplying, in a normal operating mode, energy from the first partial on-board electrical system to the second partial on-board electrical system via the first and second DC-DC converters.

10 . The method according to claim 9 , wherein, when a failure of the first DC-DC converter occurs, the on-board electrical system transitions to a first fault mode in which the second DC-DC converter supplies the second partial on-board electrical system with energy.

11 . The method according to claim 9 , wherein when a failure of the first and second DC-DC converters or of the first partial on-board electrical system occurs, the on-board electrical system transitions to a second fault mode in which the energy store supplies the second partial on-board electrical system with energy.

12 . The method according to claim 9 , wherein the second partial on-board electrical system comprises at least two parallel strands and an electrical component, and the electrical component is connected to the two parallel strands, and when a failure of one of the two parallel strands occurs, the on-board electrical system transitions to a third fault mode in which the electrical component supplies a remaining one of the two parallel strands with energy.

13 . The on-board electrical system according to claim 7 , wherein a ratio of the second on-board electrical system voltage to the first on-board electrical system voltage is in a range of 0.015 to 0.03.

14 . The on-board electrical system according to claim 7 , wherein the first on-board electrical system voltage is in a range of 400 V to 800 V and the second on-board electrical system voltage is in a range of 12 V to 48 V.

15 . The on-board electrical system according to claim 7 , wherein the motor vehicle is an autonomous motor vehicle.

16 . The on-board electrical system according to claim 7 , wherein the energy store and the high-voltage energy store are batteries.

17 . The on-board electrical system according to claim 7 , wherein the energy store is configured to compensate for voltage fluctuations that occur in the second partial on-board electrical system.

18 . The on-board electrical system according to claim 7 , wherein the first DC-DC converter and the second DC-DC converter are arranged redundantly with respect to one another.

19 . The method according to claim 9 , wherein when a failure of the first and second DC-DC converters or of the first partial on-board electrical system occurs, the on-board electrical system transitions to a second fault mode in which the energy store solely supplies the second partial on-board electrical system with energy.

Assignees

• Schaeffler Technologies Ag

Inventors

• Loehnert Victoria
• Kraus Markus
• Wuebbolt-Gorbatenko Benjamin

Classifications

• B60L1/00 Primary

  Supplying electric power to auxiliary equipment of vehicles (circuit arrangements for charging batteries H02J7/00) · CPC title

• B60L3/00

  Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption (methods or circuit arrangements for monitoring or controlling batteries or fuel cells B60L58/00) · CPC title

• B60L2210/10

  DC to DC converters · CPC title

• B60L2210/14

  Boost converters · CPC title

• B60L3/0092

  with use of redundant elements for safety purposes · CPC title