State of charge determination systems and methods

• US 9,347,997 B2
• Filed: 03/28/2011
• Issued: 05/24/2016
• Est. Priority Date: 03/28/2011
• Status: Active Grant

• Current Assignee: Changs Ascending Enterprise Co., Ltd.
• Original Assignee: Changs Ascending Enterprise Co., Ltd.
• Inventors: Chang, Chun-Chieh, Chang, Tsun Yu
• Primary Examiner(s): Muralidar, Richard V
• Application Number:
  US13/073,060
• Publication Number:
  US 20120249086A1
• Time in Patent Office: 1,884 Days
• Field of Search: 320/132, 702/63, 702/64
• US Class Current: 1/1
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements

Abstract

In one embodiment, a method implemented by a processor, comprising receiving voltage values corresponding to a battery system, receiving charge values corresponding to charge flowing through the battery system, and determining a state of charge based on specified anchoring points of a charge integration, the anchoring points based on the received voltage and time.

Claims

1. A method, comprising:

receiving, by a processor, voltage values corresponding to a battery system;

receiving, by the processor, charge values corresponding to charge flowing through the battery system;

analyzing, by the processor, at least the received voltage values over at least one defined duration period of time;

determining, by the processor, anchoring points of charge integration that satisfy respective defined conditions for respective defined duration periods of time by a defined quantity of repetition of conditions based at least in part on the received voltage and time, wherein the defined quantity of repetition is greater than 1;

updating, by the processor, a capacity of the battery system by assigning the determined anchoring points that satisfy the respective defined conditions as updated anchoring points of the charge integration thereby replacing values of previously assigned anchoring points; and

determining, by the processor, a state of charge based on the updated anchoring points of the charge integration.

2. The method of claim 1, wherein the determined anchoring points are further based on current flowing through the battery system, the current determined based on the charge and the time.

3. The method of claim 1, wherein the updating of the capacity of the battery system is further based on the charge integration between two of the updated anchoring points.

4. The method of claim 3, wherein determining the state of charge further comprises comparing an integrated charge change and the updated capacity.

5. The method of claim 1, further comprising triggering the updating during a charging process corresponding to the battery system.

6. The method of claim 1, further comprising triggering the updating during a discharging process corresponding to the battery system.

7. The method of claim 1, further comprising triggering the updating based on a defined period of time between anchoring points in which the charge integration occurs.

8. The method of claim 1, further comprising triggering the updating based on a magnitude of current attained when at least one of a pair of anchoring points of the charge integration is reached.

9. The method of claim 1, further comprising triggering the updating based on when one of a pair of anchoring points of the charge integration is reached.

10. The method of claim 1, wherein the updated anchoring points are determined by the defined quantity of repetition of conditions based on voltage, time, and current.

11. A state of charge determination system, comprising:

battery voltage sensing logic configured to sense a voltage of a battery system;

shunt voltage sensing logic configured to sense a charge flowing through the battery system; and

a processor configured to;

receive values corresponding to the sensed voltage and charge;

analyze at least the sensed voltage and charge values over at least one defined duration period of time;

determine anchoring points of charge integration that satisfy respective defined conditions for respective defined duration periods of time by a defined quantity of repetition of conditions based at least in part on the sensed voltage, time, and current, wherein the defined quantity of repetition is greater than 1;

update a capacity of the battery system by assigning the determined anchoring points that satisfy the respective defined conditions as updated anchoring points of the charge integration thereby replacing values of previously assigned anchoring points; and

determine a state of charge based on the updated anchoring points.

12. The system of claim 11, wherein the processor is further configured to update the capacity of the battery system by integrating the charge between two of the updated anchoring points.

13. The system of claim 12, wherein the processor is further configured to determine the state of charge by comparing an integrated charge change and the updated capacity.

14. The system of claim 11, wherein the processor is further configured to trigger the update during either a charging process or a discharging process corresponding to the battery system.

15. The system of claim 11, wherein the processor is further configured to trigger the update based on one or more of a defined period of time between anchoring points in which the charge integration occurs, a magnitude of current attained when at least one of the anchoring points is reached, or when one of the anchoring points is reached.

16. The system of claim 11, further comprising a display, wherein the processor is further configured to provide to the display:

a certain displayed state of charge value if the charge integration comprises a charge count that exceeds a certain value corresponding to the state of charge before a high anchoring point is reached while continuing the charge integration;

or

another displayed state of charge based on a determined new reference point for the state of charge if the charge integration comprises a charge count that does not exceed the certain value and the high anchoring point is reached.

17. The system of claim 11, further comprising a display, wherein the processor is further configured to provide to the display:

a low state of charge value if the charge integration decreases below a certain value before a low anchoring point is reached while continuing the charge integration;

or

the low state of charge value if the charge integration does not decrease below the certain value and the low anchoring point is reached, wherein the processor is further configured to continue the charge integration under new constraints.