CN112649748A - Method for determining the state of charge of a low-voltage battery of a motor vehicle - Google Patents

Method for determining the state of charge of a low-voltage battery of a motor vehicle Download PDF

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Publication number
CN112649748A
CN112649748A CN202011057328.9A CN202011057328A CN112649748A CN 112649748 A CN112649748 A CN 112649748A CN 202011057328 A CN202011057328 A CN 202011057328A CN 112649748 A CN112649748 A CN 112649748A
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China
Prior art keywords
battery
voltage
low
motor vehicle
charge
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CN202011057328.9A
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Chinese (zh)
Inventor
比约恩·莫尔曼
克里斯蒂安·施密特
丹尼斯·库兹韦尔
帕特里克·奥朴瑞
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Ford Global Technologies LLC
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Ford Global Technologies LLC
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Publication of CN112649748A publication Critical patent/CN112649748A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L1/00—Supplying electric power to auxiliary equipment of vehicles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
    • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
    • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
    • B60L58/12—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries responding to state of charge [SoC]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
    • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
    • B60L58/18—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules
    • B60L58/20—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules having different nominal voltages
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/385—Arrangements for measuring battery or accumulator variables
    • G01R31/387—Determining ampere-hour charge capacity or SoC
    • G01R31/388—Determining ampere-hour charge capacity or SoC involving voltage measurements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • H01M10/482—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte for several batteries or cells simultaneously or sequentially
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2210/00—Converter types
    • B60L2210/10—DC to DC converters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/40—Drive Train control parameters
    • B60L2240/54—Drive Train control parameters related to batteries
    • B60L2240/547—Voltage
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
    • H01M2010/4271—Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Transportation (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Energy (AREA)
  • Sustainable Development (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Physics & Mathematics (AREA)
  • Physics & Mathematics (AREA)
  • General Chemical & Material Sciences (AREA)
  • Electrochemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Secondary Cells (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)

Abstract

The invention relates to a method for determining the state of charge of a battery, in particular a low-voltage battery (14), of a motor vehicle (2), comprising the following steps: (S100) detection of a start (IB) of the motor vehicle (2), (S300) generation of a Measurement Signal (MS) for electrochemical impedance spectroscopy using a DC-DC converter (10) of the motor vehicle (2) upon detection of a start (IB) of the motor vehicle (2), and (S400) evaluation of an electrical output voltage provided by the DC-DC converter (10) and of a voltage at an electrical terminal of the battery in order to determine a state of charge (LZ) of the battery.

Description

Method for determining the state of charge of a low-voltage battery of a motor vehicle
Technical Field
The invention relates to a method for determining the state of charge of a low-voltage battery of a motor vehicle.
Background
The low-voltage battery (which may also be a starter battery, a vehicle battery or a vehicle battery) is a rechargeable battery which supplies electrical energy or a quiescent current, in particular, for a starter motor of an internal combustion engine of a motor vehicle. The low voltage battery may be used for buffer storage of an on-board electrical system of a motor vehicle (e.g., a 12 volt on-board electrical system). Low-voltage batteries can also be designed for voltage levels of up to 60V, for example rated at 24V or 48V.
A low-voltage battery is an energy storage device (hence the term "battery") consisting of a plurality of interconnected elements. It consists of rechargeable battery cells or a stack of battery cells interconnected in parallel and series.
The low-voltage battery may be a lithium-ion battery, i.e. a battery based on lithium compounds in all three phases of the electrochemical cell. However, the battery may be a lead battery, a nickel metal hydride battery, or a solid-state battery.
Particularly when used in highly automated motor vehicles, so-called robotic vehicles, there is a need for an accurate determination of the state of charge of the low voltage battery for safety reasons and to ensure reliable operation.
A Battery Management System (BMS) evaluates, among other things, the open-circuit voltage of a battery, the current flowing into and out of the battery, and the voltage under load for determining the state of charge. In the case of certain battery types, the gradient of open circuit voltage with respect to state of charge is very flat, which makes an accurate determination of the state of charge of the low-voltage battery more difficult.
Systems for determining the state of charge are known, for example, from US 2018/02030073a1, US 2016/0003917a1, US 9,428,071B2, US 2018/0364311a1, US 9,368,841B2, US2011/0270559a1 and US2017/0219660a 1.
Therefore, there is a need to show a way to improve the detection of the state of charge of a low voltage battery of a motor vehicle.
Disclosure of Invention
This object is achieved by the method according to the invention for determining the state of charge of a low-voltage battery of a motor vehicle, comprising the following steps:
the start-up of the motor vehicle is detected,
upon detection of a start of the motor vehicle, a measurement signal for electrochemical impedance spectroscopy is generated using a DC-DC converter of the motor vehicle, an
The electrical output voltage provided by the DC-DC converter and the electrical terminal voltage of the battery are evaluated in order to determine the state of charge of the low-voltage battery.
The method therefore comprises a self-test of the operational reliability of the individual components of the motor vehicle, starting from the start-up of the motor vehicle. Such a self-test or functional test may additionally or alternatively be performed at a brief stopping period (e.g., at a traffic light). The determination of the state of charge of a battery (for example a low-voltage battery of a motor vehicle) by means of electrochemical impedance spectroscopy also forms part of this self-test.
The DC-DC converter thus converts the direct current voltage of the traction battery, for example of an electric vehicle (BEV) or a hybrid vehicle (HEV), during normal operation, i.e. after start-up, into different lower values for providing a measurement signal of the electrochemical impedance spectrum. For this purpose, the following facts may be used: the DC-DC converter converts the direct voltage in the intermediate circuit (for example the direct voltage of the traction battery) into an alternating voltage and in a process step adjusts this alternating voltage up or down and then rectifies it again. Then, the alternating current voltage for the impedance spectrum is modulated to a direct current voltage. Thus, an additional inverter for generating the measurement signal can be dispensed with, and at the same time the detection of the state of charge of the low-voltage battery of the motor vehicle can be improved.
According to one embodiment, the electrical input and output currents of the DC-DC converter and the battery are additionally detected and evaluated in order to determine the state of charge of the battery. In other words, the state of charge determination is made by amp hour balancing. Thus, the amount of charge stored in and drawn from the battery is detected in a manner dependent on the mathematical sign. Therefore, the determination accuracy of the state of charge of the low-voltage battery can be improved.
According to a further embodiment, the open circuit voltage of the battery is additionally detected and evaluated in order to determine the state of charge of the battery. For this purpose, the static voltage characteristic may be pre-recorded and stored, for example in the form of a look-up table in the battery management system. This makes use of the fact that: there is an injective or strictly monotonic relationship between the static voltage (elektrischen ruhespentnung) and the state of charge of the battery. A quiescent voltage is understood to mean a voltage value that occurs after a predetermined waiting time. Once this waiting time expires, the electrochemical system of the low-voltage battery is in a dynamic equilibrium or relaxed state in which all overvoltages in the low-voltage battery based on previous charging or discharging will decrease. Therefore, the determination accuracy of the state of charge of the low-voltage battery can be further improved.
According to a further embodiment, the DC-DC converter and the low-voltage battery are DC-isolated from the electrical load of the motor vehicle in order to determine the state of charge of the low-voltage battery. For this purpose, the controllable disconnector can be opened. Thus ensuring that the load does not tamper with or affect the determination of the state of charge of the low voltage battery.
Furthermore, a computer program product, a battery management system and a DC-DC converter as well as a motor vehicle comprising such a battery management system and such a DC-DC converter form part of the present invention.
Drawings
The invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 shows a schematic diagram of components of a motor vehicle including a low voltage battery, a DC-DC converter and a traction battery;
fig. 2 shows a schematic diagram of a method sequence for operating the components shown in fig. 1.
Detailed Description
Reference is first made to fig. 1.
Components of a motor vehicle 2 are shown.
In the present exemplary embodiment, motor vehicle 2 is in the form of a passenger car. Furthermore, the motor vehicle 2 in the present exemplary embodiment is in the form of an electric or hybrid vehicle that contains a traction battery 6, which traction battery 6 is one of the components shown for storing electrical operating energy. In the present exemplary embodiment, the traction battery 6 is a lithium-ion rechargeable battery or has a lithium-ion rechargeable battery as a battery unit.
The other components shown comprise a battery management system 4, a load 8, a DC-DC converter 10 and a disconnector 12, as well as a low-voltage battery 14, the low-voltage battery 14 being used in particular for buffer storage of a 12 volt on-board electrical system of the motor vehicle 2.
The battery management system 4 is designed to monitor the low-voltage battery 14, provide closed-loop control of the low-voltage battery 14 and protect the low-voltage battery 14, and provide functions such as state of charge determination, protection against deep discharge, or overload protection.
To achieve state of charge determination, the battery management system 4 is designed to achieve electrochemical impedance spectroscopy.
Here, electrochemical impedance spectroscopy (generally abbreviated as EIS, elektrochemischen impedance zspektroskopie) is understood to mean the determination of the impedance of an electrochemical system (i.e. the ac resistance) as a function of the frequency of the ac voltage or current. The electrochemical system in the present exemplary embodiment includes the battery cells of the low-voltage battery 14.
The battery management system 4 starts the state of charge determination when a start IB of the motor vehicle 2 is detected. In other words, the battery management system 4 implements the state of charge determination as part of a self test or functional test in the same manner as it is implemented in the start-up of the motor vehicle 2. Such a self-test or functional test can additionally or alternatively be carried out, for example, during a brief parking maneuver (for example, during a traffic light).
The DC-DC converter 10 is designed to convert a direct voltage supplied at an input into a direct voltage having a higher, lower or inverted voltage level.
The basic way in which the DC-DC converter 10 functions consists in converting the direct-current voltage present at the input into a square-wave alternating-current voltage by opening and closing a switching element, for example a power transistor. By subsequent filtering, usually by means of a combination of switching elements (diodes, transistors, etc.), inductances and capacitances, the alternating voltage is converted back into a direct voltage, the voltage level of which differs from the voltage level at the input.
In the present exemplary embodiment, the DC-DC converter 10 is designed to provide a measurement signal MS for electrochemical impedance spectroscopy. The DC-DC converter 10 converts the direct current voltage of the traction battery 6 in the intermediate circuit into an alternating current voltage, which is stepped up or down and rectified again. The ac voltage for the impedance spectrum is then modulated onto the dc voltage. In other words, the measurement signal is a direct voltage, on which an alternating voltage is modulated.
For this purpose, the alternating voltage is tapped off upstream of the rectifier on the output side of the DC-DC converter 10. In other words, the DC-DC converter 10 is used twice. During normal operation, the DC-DC converter 10 converts the voltage and during the determination of the state of charge, the DC-DC converter 10 provides a measurement signal MS for electrochemical impedance spectroscopy.
In addition, in the present exemplary embodiment, the battery management system 4 is also designed to detect and evaluate the electrical input and output currents of the DC-DC converter 10 and the low-voltage battery 14 in order to improve the determination of the state of charge of the voltage battery 14 by ampere-hour balancing.
Furthermore, in the present exemplary embodiment, the battery management system 4 is also designed to detect and evaluate the static voltage of the low-voltage battery 14 in order to improve the determination of the state of charge of the low-voltage battery 14.
The load 8 is an electrical load of the motor vehicle 2, which can be operated from the voltage supplied by a low-voltage battery 14, for example an electrical load of a 12-volt on-board electrical system of the motor vehicle.
The disconnector 12 may be controlled by the DC-DC converter 10 to close or open the disconnector. When the disconnector 12 is open, the load 8 connected to the DC-DC converter 10 on the output side is DC isolated from the DC-DC converter 10 and therefore does not influence the state of charge determination.
The sequence of the method for operating the components shown in fig. 1 will now be explained with additional reference to fig. 2.
In a first step S100, the battery management system 4 detects a start IB of the motor vehicle 2. For this purpose, logical variables can be entered and evaluated, wherein a logical value is assigned to the above-mentioned logical variable for initiating the IB and a logical value of zero is assigned otherwise.
When there is a start-up IB, in a further step S200, the battery management system 4 generates a control signal AS which causes the disconnector 12 to open and thus the load 8 is DC isolated from the low-voltage battery 14 and the battery management system 4.
In a further step S300, the battery management system 4 then generates a measurement signal MS for electrochemical impedance spectroscopy.
In a further step S400, the battery management system 4 evaluates the electrical output voltage of the DC-DC converter 10 and the electrical terminal voltage of the low-voltage battery 14 in order to determine the state of charge LZ of the low-voltage battery 14.
In addition, the battery management system 4 may be provided to detect and evaluate the electrical input and output currents of the DC-DC converter 10 and the low-voltage battery 14 for ampere-hour balancing and/or the quiescent voltage of the low-voltage battery 14 in order to improve the determination accuracy of the state of charge LZ of the low-voltage battery 14.
The order of the steps may also be different as a departure from the present exemplary embodiment. Furthermore, several steps may also be performed simultaneously or concurrently. In addition, the respective steps may be omitted or skipped.
Thus, an inverter for generating the measurement signal can be dispensed with and at the same time the detection of the state of charge of the low-voltage battery 14 of the motor vehicle 2 can be improved.
List of reference numerals
2 Motor vehicle
4 Battery management system
6 traction battery
8 load
10 DC-DC converter
12 isolating switch
14 low voltage battery
AS control signal
IB Start
LZ State of Charge
MS measurement signals

Claims (11)

1. A method for determining the state of charge of a low-voltage battery (14) of a motor vehicle (2), comprising the steps of:
(S100) detecting a start (IB) of the motor vehicle (2),
(S300) generating a Measurement Signal (MS) for electrochemical impedance spectroscopy using a DC-DC converter (10) of the motor vehicle (2) upon detection of a start (IB) of the motor vehicle (2), and
(S400) evaluating an electrical output voltage provided by the DC-DC converter (10) and an electrical terminal voltage of the battery in order to determine a state of charge (LZ) of the battery.
2. The method according to claim 1, wherein the electrical input and output currents of the DC-DC converter (10) and the low-voltage battery (14) are additionally detected and evaluated in order to determine the state of charge (LZ) of the low-voltage battery (14).
3. Method according to claim 1 or 2, wherein the open circuit voltage of the low-voltage battery (14) is additionally detected and evaluated in order to determine the state of charge (LZ) of the low-voltage battery (14).
4. A method according to claim 1, 2 or 3, wherein, in a further step (S200), the DC-DC converter (10) and the low-voltage battery (14) are DC-isolated from an electrical load (8) of the motor vehicle (2) in order to determine the state of charge (LZ) of the low-voltage battery (14).
5. Computer program product designed to perform the method according to any one of claims 1 to 4.
6. Battery management system (4), wherein the battery management system (4) is designed to detect a start (IB) of a motor vehicle (2), to generate a Measurement Signal (MS) for an electrochemical impedance spectrum using a DC-DC converter (10) of the motor vehicle (2) upon detection of the start (IB) of the motor vehicle (2), and to evaluate an electrical output voltage provided by the DC-DC converter (10) and in particular an electrical terminal voltage of a battery of a low-voltage battery (14) in order to determine a state of charge (LZ) of the battery.
7. The battery management system (4) according to claim 6, wherein the battery management system (4) is additionally designed to detect and evaluate electrical input and output currents of the DC-DC converter (10) and the low-voltage battery (14) in order to determine the state of charge (LZ) of the low-voltage battery (14).
8. The battery management system (4) according to claim 6 or 7, wherein the battery management system (4) is additionally designed to detect and evaluate the open circuit voltage of the low-voltage battery (14) in order to determine the state of charge (LZ) of the low-voltage battery (14).
9. The battery management system (4) according to claim 6, 7 or 8, wherein the battery management system (4) is designed to DC-isolate the DC-DC converter (10) and the low-voltage battery (14) from an electrical load (8) of the motor vehicle (2) in order to determine the state of charge (LZ) of the low-voltage battery (14).
A DC-DC converter (10), wherein the DC-DC converter (10) is designed to provide a Measurement Signal (MS) for electrochemical impedance spectroscopy to determine a state of charge of a low-voltage battery (14) of a motor vehicle (2).
11. Motor vehicle (2), the motor vehicle (2) comprising a battery management system (4) according to any of claims 6 to 9 and a DC-DC converter (10) according to claim 10.
CN202011057328.9A 2019-10-09 2020-09-29 Method for determining the state of charge of a low-voltage battery of a motor vehicle Pending CN112649748A (en)

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DE102019127179.7A DE102019127179A1 (en) 2019-10-09 2019-10-09 Method for determining the state of charge of a low-voltage battery of a motor vehicle
DE102019127179.7 2019-10-09

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113696781A (en) * 2021-08-10 2021-11-26 岚图汽车科技有限公司 New energy automobile OTA upgrade storage battery capacity detection method and system

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9368991B2 (en) * 2012-10-30 2016-06-14 The Board Of Trustees Of The University Of Alabama Distributed battery power electronics architecture and control
DE102017201485A1 (en) * 2017-01-31 2018-08-02 Siemens Aktiengesellschaft A method and arrangement for determining the charge capacity and health of an electrical energy store

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113696781A (en) * 2021-08-10 2021-11-26 岚图汽车科技有限公司 New energy automobile OTA upgrade storage battery capacity detection method and system

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