BATTERY MANAGEMENT SYSTEM AND DRIVING METHOD THEREOF

• US 20080065336A1
• Filed: 09/06/2007
• Published: 03/13/2008
• Est. Priority Date: 09/08/2006
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Choi, Soo-Seok, Lee, Young-Jo, Kim, Beom-Gyu, Seo, Se-Wook, Lim, Gye-Jong, Yun, Han-Seok, Tae, Yong-Jun
• Granted Patent: US 7,684,941 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/005 Testing of electric installations on transport means
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• 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]
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery management system to estimate a state of charge of a battery and a driving method thereof includes a sensing unit and a micro control unit. The sensing unit measures a battery voltage. The MCU measures a first time and a second time, detects first and second battery voltages that respectively correspond to the first and second times from the battery voltage, estimates an open circuit voltage by the first and second voltages, and establishes the SOC that corresponds to the OCV.

Claims

1. A battery management system used to establish a state of charge (SOC) of a battery used in the battery management system, the battery management system comprising:

a sensing unit to measure a battery voltage; and

a micro control unit (MCU) to measure a first time and a second time, to detect first and second battery voltages that respectively correspond to the first and second times from the battery voltage, to estimate an open circuit voltage (OCV) by the first and second voltages, and to determine the SOC that corresponds to the OCV.

2. The battery management system of claim 1, wherein the first time is measured when an effect of an internal resistance of the battery is eliminated, and the second time is measured after a predetermined period has passed from the first time to dissipate polarization caused by electrolyte diffusion.

3. The battery management system of claim 1, wherein the MCU comprises:

an OCV estimator to estimate the OCV by using the first and second voltages; and

an SOC establishment unit to receive the OCV and to determine the SOC that corresponds to the OCV.

4. The battery management system of claim 1, further comprising an OCV estimator, wherein the OCV estimator generates a linear equation given as

5. A driving method of a battery management system to establish a state of charge (SOC) of a battery used in the battery management system, the driving method comprising:

when the battery is not charged and/or discharged, measuring a first time and a second time, and detecting a first battery voltage that corresponds to the first time and a second battery voltage that corresponds to the second time;

generating a linear equation that includes the first time, the first battery voltage, the second time, and the second battery voltage; and

estimating an open circuit voltage (OCV) of the battery by using the linear equation.

6. The driving method of claim 5, wherein, the generating of the linear equation includes generating the linear equation given as

7. The driving method of claim 6, further comprising:

receiving the estimated OCV;

using a table to determine the SOC that corresponds to the OCV; and

determining the SOC.

8. A computer readable medium recorded with a program for a computer to execute a method of driving a battery management system to establish a state of charge (SOC) of a battery used in the battery management system, wherein the computer executes the method of claim 5.

9. A driving method of a battery management system to obtain a state of charge (SOC) of a rechargeable battery, the driving method comprising:

measuring at least two times;

detecting at least two voltages of the rechargeable battery that correspond to respective ones of the at least two times;

determining an open circuit voltage (OCV) of the rechargeable battery based on the at least two times and the at least two voltages; and

determining the SOC of the rechargeable battery that corresponds to the determined OCV.

10. The driving method of the battery management system of claim 9, wherein the at least two times are measured based on when an effect of an internal resistance of the battery is eliminated, after a predetermined period has passed to dissipate polarization caused by electrolyte diffusion, or any combination thereof.

11. The driving method of the battery management system of claim 9, wherein the OCV is a Y-intercept of a line equation obtained based on the at least two times and the at least two voltages.

12. A method to obtain a state of charge (SOC) of a rechargeable battery, the method comprising:

detecting voltage of the rechargeable battery corresponding to time;

determining an open circuit voltage (OCV) of the rechargeable battery using an inverse relationship of the time relative to the voltage; and

determining the SOC of the rechargeable battery that corresponds to the determined OCV.