Electrical System and Method for Operating an Electrical System

• US 20160347197A1
• Filed: 01/23/2015
• Published: 12/01/2016
• Est. Priority Date: 01/27/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Samsung SDI Company Limited
• Original Assignee: Robert Bosch GmbH
• Inventors: Fink, Holger
• Granted Patent: US 10,071,646 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2260/20 Drive modes; Transition between modes
• CPC Class Codes: B60L 2260/22 Standstill, e.g. zero speed
• CPC Class Codes: B60L 2260/24 Coasting mode
• CPC Class Codes: B60L 2260/26 Transition between different drive modes
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/19 Switching between serial connection and parallel connection of battery modules
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60R 16/033 characterised by the use of electrical cells or batteries for propulsion puposes B60K1/04; supplying batteries to, or removing batteries from, vehicles B60S5/06; testing of charge state G01R31/36
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0024 Parallel/serial switching of connection of batteries to charge or load circuit
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y10S 903/907 Electricity storage, e.g. battery, capacitor

Abstract

The disclosure relates to an electrical system for a vehicle, comprising a low-voltage sub-network for at least one low-voltage load and comprising a high-voltage sub-network for at least one high-voltage load and an electric generator. The high-voltage sub-network has a battery which is designed to generate a high-voltage and output same to the high-voltage sub-network and which has at least two battery units with individual voltage taps. The high-voltage sub-network is connected to the low-voltage sub-network via a coupling unit which is designed to draw energy from the high-voltage sub-network and supply said energy to the low-voltage sub-network. The coupling unit is designed to selectively connect the battery units to the low-voltage sub-network. The disclosure further relates to a method for operating an electrical system, to a motor vehicle, and to a battery management system and a computer program which are designed to carry out the method.

Claims

1. An onboard electrical system for a motor vehicle, having

a low voltage subsystem for at least one low voltage load configured to operate with a low voltage;

a high voltage subsystem for at least one high voltage load configured to operate with a high voltage, the high voltage subsystem having a battery configured to produce the high voltage and to output the high voltage to the high voltage subsystem, the battery having at least two battery units having individual voltage taps;

an electrical generator; and

a coupling unit configured to connect the high voltage subsystem to the low voltage subsystem the coupling unit being configured to draw power from the high voltage subsystem and to supply the power to the low voltage subsystem, the individual voltage taps of the at least two battery units being routed to the coupling unit, the coupling unit being configured to selectively connect the battery units to the low voltage subsystem.

2. The onboard electrical system as claimed in claim 1, wherein the battery units are each configured to provide the low voltage.

3. The onboard electrical system as claimed in claim 1, wherein the coupling unit includes switches with reverse blocking capability.

4. The onboard electrical system as claimed in claim 1, wherein the low voltage subsystem includes at least one energy store configured to produce the low voltage and to output the low voltage to the low voltage subsystem.

5. The onboard electrical system as claimed in claim 1, wherein the low voltage subsystem includes a starter.

6. A method for operating an onboard electrical system for a motor vehicle, the onboard electrical system including (i) a low voltage subsystem for at least one low voltage load configured to operate with a low voltage, (ii) and a high voltage subsystem for at least one high voltage load configured to operate with a high voltage, the high voltage subsystem having a battery configured to produce the high voltage and to output the high voltage to the high voltage subsystem, the battery having at least two battery units having individual voltage taps, (iii) an electrical generator, and (iv) a coupling unit configured to connect the high voltage subsystem to the low voltage subsystem, the individual voltage taps of the at least two battery units being routed to the coupling unit, the coupling unit being configured to selectively connect the battery units to the low voltage subsystem, the method comprising:

connecting the battery unit that has a highest state of charge to the low voltage subsystem with the coupling unit;

drawing power from the high voltage subsystem with the coupling unit; and

supplying the power to the low voltage subsystem with the coupling unit.

7. The method as claimed in claim 6, further comprising:

changing which of the battery units is connected to the low voltage subsystem in response to a charge difference of the battery units exceeding.

8. The method as claimed in claim 6, further comprising:

disconnecting a current-carrying battery unit of the battery units; and

connecting, thereafter, a selected further battery unit of the battery units.

9. The method as claimed in claim 6, wherein the method is performed by a battery management system the method further comprising:

ascertaining a state of charge of the battery units using a first unit of battery management system; and

controlling the coupling unit to selectively connect battery units on the basis of the ascertained states of charge of the battery units using a second unit of battery management system.

10. The method as claimed in claim 6, wherein the method is performed by a computer program that is executed on a programmable computer device.

11. A motor vehicle comprising:

an internal combustion engine; and

an onboard electrical system, the onboard electrical system comprising;

a low voltage subsystem for at least one low voltage load configured to operate with a low voltage;

a high voltage subsystem for at least one high voltage load configured to operate with a high voltage, the high voltage subsystem having a battery configured to produce the high voltage and to output the high voltage to the high voltage subsystem, the battery having at least two battery units having individual voltage taps;

an electrical generator; and

a coupling unit configured to connect the high voltage subsystem to the low voltage subsystem, the coupling unit being configured to draw power from the high voltage subsystem and to supply power to the low voltage subsystem, the individual voltage taps of the at least two battery units being routed to the coupling unit, the coupling unit being configured to selectively connect the battery units to the low voltage subsystem.