Battery capacity estimation apparatus and method, and battery management apparatus provided with same and method thereof

• US 11,391,779 B2
• Filed: 09/18/2018
• Issued: 07/19/2022
• Est. Priority Date: 10/11/2017
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Energy Solution Limited (LG Corporation)
• Inventors: Hong, Sung Ju, Kim, Dong Hyun, Yoon, Seog Jin
• Primary Examiner(s): Williams, Arun C
• Application Number:
  US16/623,860
• Publication Number:
  US 20200132782A1
• Time in Patent Office: 1,400 Days
• Field of Search: None
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/388 involving voltage measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/007182 in response to battery voltage

Abstract

A battery capacity estimation apparatus including: a battery; a sensing unit connected to the battery to measure an OCV of the battery; an SOC estimation unit connected to the sensing unit to estimate an SOC of the battery using the OCV measured from the sensing unit; a memory unit storing data including the SOC and the OCV of the battery, the memory unit being connected to the SOC estimation unit; and an operation unit connected to the SOC estimation unit and the memory unit, the operation unit being configured to calculate an SOC reduction degree according to a use voltage range change and re-calculate a changed SOC according to a changed use capacity.

Claims

1. A battery capacity estimation apparatus comprising:

a battery;

a sensing unit connected to the battery to measure an OCV of the battery;

an SOC estimation unit connected to the sensing unit to estimate an SOC of the battery using the OCV measured from the sensing unit;

a memory unit configured to store data including the SOC and the OCV of the battery, the memory unit being connected to the SOC estimation unit; and

an operation unit connected to the SOC estimation unit and the memory unit, the operation unit being configured to calculate an SOC reduction degree according to a use voltage range change and re-calculate a changed SOC based on a changed use capacity of the battery,

wherein the use voltage range change is a reduction in usable voltage of the battery from an initial voltage range of the battery and is based on the changed use capacity of the battery, and

wherein the changed use capacity of the battery is a reduction in a usable capacity of the battery from an initial usable capacity of the battery.

2. The apparatus of claim 1, wherein the memory unit matches and stores a plurality of initial SOCs and a plurality of initial OCVs, and matches and stores a plurality of changed SOCs and a plurality of changed OCVs.

3. The apparatus of claim 1, wherein the operation unit calculates a changed capacity by [Equation 1] below.

X′

[mAh]=X[mAh]×

(1−

(A%+B%))  

 

[Equation 1]

where X′

is a changed capacity, X is an initial capacity, A and B are high and low capacity subtraction ratios, respectively.

4. The apparatus of claim 3, wherein the operation unit calculates a changed SOC by [Equation 2] below

17. The apparatus of claim 1, wherein the use voltage range is less than an original voltage range of the battery.

5. A battery management apparatus comprising:

a battery;

a sensing unit connected to the battery to measure an OCV of the battery;

an SOC estimation unit connected to the sensing unit to estimate an SOC of the battery using the OCV measured from the sensing unit;

a memory unit configured to store data including the SOC and the OCV of the battery, the memory unit being connected to the SOC estimation unit;

an operation unit connected to the SOC estimation unit and the memory unit and configured to calculate an SOC reduction degree according to a use voltage range change and re-calculate a changed SOC based on a changed use capacity;

a control unit connected to at least one of the operation unit and the memory unit to control charging and discharging of the battery according to a state of the battery based on the re-calculated changed SOC; and

a switching unit provided between the battery and a load to charge/discharge the battery according to a control signal of the control unit,

wherein the use voltage range change is a reduction in usable voltage of the battery from an initial voltage range of the battery and is based on the changed use capacity of the battery, and

wherein the changed use capacity of the battery is a reduction in a usable capacity of the battery from an initial usable capacity of the battery.

6. The apparatus of claim 5, wherein the operation unit calculates a changed capacity by [Equation 1] below and calculates a changed SOC by [Equation 2] below

X′

[mAh]=X[mAh]×

(1−

(A%+B%))  

 

[Equation 1]

where X′

is a changed capacity, X is an initial capacity, A and B are high and low capacity subtraction ratios, respectively,

18. The apparatus of claim 5, wherein the use voltage range is less than an original voltage range of the battery.

7. A battery capacity estimation method comprising:

measuring an OCV of a battery;

estimating an initial SOC according to the measured OCV;

calculating a changed SOC after calculating a SOC reduction degree according to a use voltage range change; and

calculating a changed OCV according to the changed SOC,

wherein the use voltage range change is a reduction in usable voltage of the battery from an initial voltage range of the battery and is based on the changed use capacity of the battery, and

wherein the changed use capacity of the battery is a reduction in a usable capacity of the battery from an initial usable capacity of the battery.

8. The method of claim 7, further comprising matching and storing a plurality of initial SOCs of the battery and a plurality of initial OCVs according thereto.

9. The method of claim 8, wherein the initial SOC is estimated by matching the measured OCV and the initial OCV.

10. The method of claim 7, wherein the calculating of the changed SOC comprises:

calculating a SOC change degree according to the use voltage range change;

calculating a changed capacity by subtracting from the initial capacity by the SOC change degree; and

calculating the changed SOC.

11. The method of claim 10, wherein the changed capacity is calculated by [Equation 1] below

X′

[mAh]=X[mAh]×

(1−

(A%+B%))  

 

[Equation 1]

where X′

is a changed capacity, X is an initial capacity, A and B are high and low capacity subtraction ratios, respectively.

12. The method of claim 10, wherein the changed SOC is calculated by [Equation 2] below

13. The method of claim 7, further comprising storing a plurality of data by matching the changed SOC and the changed OCV.

19. The method of claim 7, wherein the use voltage range is less than an original voltage range of the battery.

14. A battery management method comprising:

measuring an OCV of a battery;

estimating an initial SOC according to the measured OCV;

calculating a changed SOC after calculating a SOC reduction degree according to a use voltage range change;

calculating a changed OCV according to the changed SOC; and

controlling charging/discharging of the battery according to the state of the battery based on the changed SOC,

wherein the use voltage range change is a reduction in usable voltage of the battery from an initial voltage range of the battery and is based on the changed use capacity of the battery, and

wherein the changed use capacity of the battery is a reduction in a usable capacity of the battery from an initial usable capacity of the battery.

15. The method of claim 14, wherein the calculating of the changed SOC comprises:

calculating a SOC change degree according to the use voltage range change;

calculating a changed capacity by subtracting from the initial capacity by the SOC change degree; and

calculating the changed SOC.

16. The method of claim 15, wherein the changed capacity is calculated by [Equation 1] below and the changed SOC is calculated by [Equation 2] below

X′

[mAh]=X[mAh]×

(1−

(A%+B%))  

 

[Equation 1]

where X′

is a changed capacity, X is an initial capacity, A and B are high and low capacity subtraction ratios, respectively, and

20. The method of claim 14, wherein the use voltage range is less than an original voltage range of the battery.