Battery aging state calculation method and device

Patent metadata

Field	Value
Publication number	US-11041913-B2
Application number	US-201715799475-A
Country	US
Kind code	B2
Filing date	Oct 31, 2017
Priority date	Nov 1, 2016
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

The present disclosure relates to a battery aging state calculation method and device, and more particularly, to a battery aging state calculation method and device for calculating a (i.e., State of Health (SOH)) according to each execution operation and calculating a final battery SOH based on charge/discharge execution counts to improve the accuracy of the battery SOH.

First claim

What is claimed is:

1. A method of calculating an aging state (i.e., State of Health (SOH)) of a battery, the method comprising:
a measurement operation for measuring a current, a voltage, and a temperature at an execution start and end time for each charge and discharge operation during a charge and discharge operation execution in a target battery for a predetermined time;
a State of Charge (SOC) change amount estimation operation for estimating a change amount of an SOC at a start and end time point of each of the charge and discharge operation based on the current, voltage, and temperature measured in the measurement operation;
an SOH calculation operation for calculating an SOH according to each charge and discharge operation based on an absolute value of the SOC change amount calculated in the SOC change amount calculation operation of each of the charge and discharge operation, wherein when an SOC change amount calculated in the SOC change amount estimation operation is a negative number, the SOH calculation operation converts the negative number into a positive number to calculate the SOH; and
an final SOH calculation operation for calculating a final SOH by applying a weight according to a charge and discharge count to each SOH calculated in the SOH calculation operation.

2. The method of claim 1 , wherein the measurement operation further comprises:
a charge current integration operation for integrating a current charged during a charge execution; and
a discharge current integration operation for integrating a current discharged during a discharge execution.

3. The method of claim 2 , wherein the SOH calculation operation comprises:
a charge SOH calculation operation for calculating an SOH value during a charge execution by using a pre-stored nominal capacity, a charge current amount integrated in the charge current integration operation, and an SOC change amount calculated in the SOC change amount estimation operation during a charge execution; and
a discharge SOH calculation operation for calculating an SOH value during a discharge execution by using a pre-stored nominal capacity, a discharge current amount integrated in the discharge current integration operation, and an SOC change amount calculated in the SOC change amount estimation operation during a discharge execution.

4. The method of claim 1 , wherein when charge/discharge occurs at a same time, the final SOH calculation operation classifies as a charge or discharge state according to a sign of the SOC change amount calculated in the SOC change amount calculation operation.

5. A device for calculating an aging state (i.e., State of Health (SOH)) of a battery, the device comprising:
a measurement unit for measuring a current, a voltage, and a temperature at an execution start and end time for each charge and discharge operation during a charge and discharge execution in a target battery for a predetermined time;
a State of Charge (SOC) estimation unit for estimating an SOC at an execution start and end time for each charge and discharge operation based on the current, voltage, and temperature measured in the measurement unit;
an SOC change amount calculation unit for calculating a change amount of SOC according to each charge and discharge operation estimated by the SOC estimation unit;
an SOH calculation unit for calculating an SOH of each charge and discharge operation based on an absolute value of the SOC change amount calculated in the SOC change amount calculation unit for each charge and discharge operation; and
a final SOH calculation unit for calculating a final SOH by applying a weight according to a charge and discharge count to each SOH calculated in the SOH calculation unit.

6. The device of claim 5 , wherein the measurement unit further comprises:
a charge current integration unit for integrating a current charged during a charge execution; and
a discharge current integration unit for integrating a current discharged during a discharge execution.

7. The device of claim 6 , wherein the SOH calculation unit comprises:
a charge SOH calculation unit for calculating an SOH value during a charge execution by using a pre-stored nominal capacity, a charge current amount integrated in the charge current integration unit, and an SOC change amount calculated in the SOC estimation unit during a charge execution; and
a discharge SOH calculation unit for calculating an SOH value during a discharge execution by using a pre-stored nominal capacity, a discharge current amount integrated in the discharge current integration unit, and an SOC change amount calculated in the SOC estimation unit during a discharge execution.

8. The device of claim 5 , wherein when charge/discharge occurs at a same time, the final SOH calculation unit classifies as a charge or discharge state according to a sign of the SOC change amount calculated in the SOC change amount calculation unit.

9. A method of estimating a remaining battery lifetime, the method comprising:
a measurement operation for measuring a current, a voltage, and a temperature at an execution start and end time for each charge and discharge operation during a charge and discharge operation execution in a target battery for a predetermined time;
a State of Charge (SOC) change amount estimation operation for estimating a change amount of an SOC at a start and end time point of each of the charge and discharge operation based on the current, voltage, and temperature measured in the measurement operation;
a battery lifetime estimation operation for calculating an estimated battery lifetime according to each charge and discharge operation based on each SOC change amount calculated in the SOC change amount calculation operation; and
an final battery lifetime estimation operation for estimating a final SOH by applying a weight according to a charge and discharge count to each estimated battery lifetime calculated in the battery lifetime estimation operation.

10. The method of claim 9 , further comprising a current integration operation for calculating an integrated charged current during the charge operation and an integrated discharged current during the discharge operation, wherein the estimated battery lifetime according to the charge operation is based further on the integrated charged current, and wherein the estimated battery lifetime according to the discharge operation is based further on the integrated discharged current.

Assignees

• Lg Chemical Ltd

Inventors

• Choi Hae In
• Lee Jong Bum

Classifications

• G01R31/388

  involving voltage measurements · CPC title

• G01R31/3828

  using current integration · CPC title

• G01R31/3648

  comprising digital calculation means, e.g. for performing an algorithm · CPC title

• G01R31/3842

  combining voltage and current measurements · CPC title

• B60L58/16

  responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH] · CPC title