Power storage module state estimation apparatus, battery pack, and method for estimating the state of a power storage module

• US 9,658,289 B2
• Filed: 02/23/2015
• Issued: 05/23/2017
• Est. Priority Date: 03/04/2014
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Uchino, Manabu, Arai, Narumi
• Primary Examiner(s): Diao, M'Baye
• Application Number:
  US14/628,861
• Publication Number:
  US 20150253389A1
• Time in Patent Office: 820 Days
• Field of Search: 324427, 702 63
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3828 using current integration
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]

Abstract

According to an example embodiment of the present disclosure, a power storage module state estimation apparatus comprises a parameter calculator configured to calculate a parameter based on a current value of a power storage module, wherein the parameter includes at least one of a direction having a high frequency of current flowing in the power storage module, an average current value of the power storage module, and a charge and discharge capacity after the direction having the high frequency of current flowing in the power storage module is switched; and a hysteresis compensator configured to use the parameter to compensate an open circuit voltage of the power storage module.

Claims

1. A power storage module state estimation apparatus comprising:

a parameter calculator configured to calculate a parameter based on a current value of a power storage module, wherein the parameter is selected from the group consisting of a direction of a current having a high frequency of current and flowing in the power storage module, an average current value of the power storage module, and a charge and discharge capacity after the direction of the current having the high frequency of current and flowing in the power storage module is switched;

a hysteresis compensator configured to use the parameter to compensate an open circuit voltage of the power storage module;

an open circuit voltage calculator configured to calculate the open circuit voltage of the power storage module; and

an open circuit voltage validity determination module configured to determine whether the open circuit voltage calculated by the open circuit voltage calculator is valid.

2. The power storage module state estimation apparatus according to claim 1, wherein using a compensated open circuit voltage of the power storage module improves accuracy of an estimation of a state of charge of the power storage module.

3. The power storage module state estimation apparatus according to claim 1, further comprising a charging state calculator configured to calculate a charging state value of the power storage module using a compensated open circuit voltage of the power storage module.

4. The power storage module state estimation apparatus according to claim 3, further comprising an open circuit voltage curve calculator configured to calculate an open circuit voltage curve of the power storage member based on the charging state value calculated by the charging state calculator.

5. The power storage module state estimation apparatus according to claim 4, further comprising a deterioration state calculator configured to calculate a deterioration state value of the power storage member based on the open circuit voltage curve calculated by the open circuit voltage curve calculator.

6. The power storage module state estimation apparatus according to claim 1, further comprising a temperature reader configured to provide a temperature of the power storage module to the hysteresis compensator for compensating the open circuit voltage of the power storage module.

7. The power storage module state estimation apparatus according to claim 1, wherein at least one of a hybrid vehicle and an electric vehicle includes the power storage module.

8. The power storage module state estimation apparatus according to claim 1, wherein a building includes the power storage module.

9. The power storage module state estimation apparatus according to claim 1, wherein the power storage module is a secondary battery.

10. The power storage module state estimation apparatus according to claim 1, wherein the power storage module is a hybrid capacitor.

11. A battery pack comprising:

a power storage module;

a parameter calculator configured to calculate a parameter based on a current value of the power storage module, wherein the parameter is selected from the group consisting of a direction of a current having a high frequency of current and flowing in the power storage module, an average current value of the power storage module, and a charge and discharge capacity after a direction of a dominant current flow is switched;

a hysteresis compensator configured to use the parameter to compensate an open circuit voltage of the power storage module;

an open circuit voltage calculator configured to calculate the open circuit voltage of the power storage module; and

an open circuit voltage validity determination module configured to determine whether the open circuit voltage calculated by the open circuit voltage calculator is valid.

12. The battery pack according to claim 11, wherein the power storage module is a lithium ion secondary battery using an olivine-type iron phosphate as the cathode material.

13. The battery pack according to claim 11, further comprising a temperature measurement circuit.

14. The battery pack according to claim 11, wherein the battery pack is configured to be connected to an electronic device.

15. A method for estimating the state of a power storage module comprising:

Calculating, by a parameter calculator, a parameter based on a current value of a power storage module, wherein the parameter is selected from the group consisting of a direction of a current having a high frequency of current and flowing in the power storage module, an average current value of the power storage module, and a charge and discharge capacity after the direction of the current having the high frequency of current and flowing in the power storage module is switched; and

Compensating, by a hysteresis compensator, an open circuit voltage of the power storage module based on the parameter;

Calculating, by an open circuit voltage calculator, the open circuit voltage of the power storage module; and

determining, by an open circuit validity determination module, whether the calculated open circuit voltage is valid.

16. The method according to claim 15, wherein using a compensated open circuit voltage of the power storage module improves accuracy of an estimation of a state of charge of the power storage module.

17. A power storage module state estimation apparatus comprising:

a parameter calculator configured to calculate a parameter based on a current value of a power storage module, wherein the parameter is selected from the group consisting of a direction of a current having a high frequency of current and flowing in the power storage module, an average current value of the power storage module, and a charge and discharge capacity after the direction of the current having the high frequency of current and flowing in the power storage module is switched;

a hysteresis compensator configured to use the parameter to compensate an open circuit voltage of the power storage module;

a charging state calculator configured to calculate a charging state value of the power storage module using a compensated open circuit voltage of the power storage module;

an open circuit voltage curve calculator configured to calculate an open circuit voltage curve of the power storage module based on the charging state value calculated by the charging state calculator; and

a deterioration state calculator configured to calculate a deterioration state value of the power storage module based on the open circuit voltage curve calculated by the open circuit voltage curve calculator.

18. A battery pack comprising:

a power storage module;

a parameter calculator configured to calculate a parameter based on a current value of the power storage module, wherein the parameter is selected from the group consisting of a direction of a current having a high frequency of current and flowing in the power storage module, an average current value of the power storage module, and a charge and discharge capacity after a direction of a dominant current flow is switched;

a hysteresis compensator configured to use the parameter to compensate an open circuit voltage of the power storage module;

a charging state calculator configured to calculate a charging state value of the power storage module using a compensated open circuit voltage of the power storage module;

an open circuit voltage curve calculator configured to calculate an open circuit voltage curve of the power storage module based on the charging state value calculated by the charging state calculator;

and a deterioration state calculator configured to calculate a deterioration state value of the power storage module based on the open circuit voltage curve calculated by the open circuit voltage curve calculator.