Battery management system using a resistor and driving method thereof

• US 8,174,240 B2
• Filed: 09/13/2007
• Issued: 05/08/2012
• Est. Priority Date: 11/01/2006
• Status: Expired due to Fees

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Yun, Han-Seok, Choi, Soo-Seok, Lee, Young-Jo, Tae, Yong-Jun, Seo, Se-Wook, Lim, Gye-Jong, Kim, Beom-Gyu, Park, Ho-Young
• Primary Examiner(s): WILLIAMS, ARUN C
• Application Number:
  US11/854,865
• Publication Number:
  US 20080100298A1
• Time in Patent Office: 1,699 Days
• Field of Search: 320/132, 320/DIG.22, 324/430
• US Class Current: 320/132
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• 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: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery management system and a driving method include a first switch coupled to an end of a resistor. When calculating an internal resistance of a battery, the first switch is turned on and the battery and the resistor are coupled in parallel. Then, the internal resistance of the battery is calculated by using a second current flowing to the battery and a first current flowing to the resistor.

Claims

1. A battery management system comprising:

a resistor configured to be coupled in series

between a battery and a first power source, and

between an external source and the first power source; and

a first switch coupled between one end of the resistor and the first power source,

wherein the battery management system is configured to calculate an internal resistance of the battery while charging the battery from the external source and while discharging the battery to the external source by;

turning on the first switch to couple the resistor in series

between the battery and the first power source when discharging the battery to the external source, and

between the external source and the first power source when charging the battery from the external source; and

calculating the internal resistance of the battery by using a value of a first current flowing to the resistor and a value of a second current flowing to/from the battery.

2. The battery management system of claim 1, wherein the battery management system is further configured to calculate the internal resistance of the battery by using the following equation:

3. The battery management system of claim 2, further comprising:

a second switch coupled between the battery and an inverter in series, the second switch for transmitting the charging and discharging current between the battery and the external source; and

a third switch coupled to the second switch in parallel, the third switch for turning on when the battery is initially discharged or initially charged to prevent an initial in-rush current from flowing between the battery and the external source.

4. The battery management system of claim 3, wherein the resistor is a precharge resistor used to control a voltage between the battery and the inverter when the battery is initially charged or initially discharged.

5. The battery management system of claim 2, wherein the resistor is a precharge resistor used to control a voltage between the battery and an inverter when the battery is initially charged or initially discharged.

6. The battery management system of claim 1, wherein the resistor is a precharge resistor used to control a voltage between the battery and an inverter when the battery is initially charged or initially discharged.

7. The battery management system of claim 1, wherein the battery is for use in an electric or hybrid vehicle.

8. A battery management system to manage a battery, the battery management system comprising:

a resistor configured to be coupled in series

between the battery and a first power source; and

between an external source and the first power source;

a first current sensor to measure a first current flowing to the resistor;

a first switch having a first end coupled to the resistor and a second end coupled to the first power source having a first voltage; and

a main control unit (MCU) to;

turn on the first switch to couple the resistor in series

between the battery and the first power source when discharging the battery to the external source, and

between the external source and the first power source when charging the battery from the external source; and

calculate an internal resistance of the battery while charging the battery from the external source and while discharging the battery to the external source by using a value of a second current flowing to/from the battery and a value of the first current flowing to the resistor.

9. The battery management system of claim 8, further comprising:

a second current sensor to measure a charging and discharging current of the external source;

a second switch coupled between the battery and an inverter in series, the second switch having a first end coupled to the first current sensor and a second end coupled to the second current sensor, the second switch for transmitting the charging and discharging current between the battery and the external source to charge and discharge the battery; and

a third switch coupled to the second end of the second switch in parallel and coupled to a first end of the resistor, the third switch for turning on when the battery is initially discharged or initially charged to prevent an initial in-rush current from flowing between the battery and the external source.

10. The battery management system of claim 9, wherein the resistor is a precharge resistor used to control a voltage between the battery and the inverter.

11. The battery management system of claim 8, wherein the resistor is a precharge resistor used to control a voltage between the battery and an inverter.

12. The battery management system of claim 8, wherein the battery is for use in an electric or hybrid vehicle.

13. A driving method to drive a battery management system that manages a battery, the driving method comprising:

selectively coupling a resistor in series

between the battery and a first power source, and

between an external source and the first power source by using a first switch coupled between one end of the resistor and the first power source;

measuring a second current flowing to/from the battery while charging the battery from the external source and while discharging the battery to the external source;

measuring a first current flowing to the resistor

while charging the battery from the external source when the resistor is selectively coupled in series between the external source and the first power source, and

while discharging the battery to the external source when the resistor is selectively coupled in series between the battery and the first power source; and

calculating an internal resistance of the battery by using a value of the first current and a value of the second current.

14. The driving method of claim 13, wherein the selectively coupling of the resistor comprises selectively coupling the one end of the resistor with the first power source having a first voltage during the measuring of the first current.

15. The driving method of claim 14, wherein the first voltage is a ground voltage.

16. The driving method of claim 14, wherein the calculating of the internal resistance comprises calculating the internal resistance of the battery by using the following equation:

17. The driving method of claim 16, wherein the resistor is a precharge resistor used to control a voltage between the battery and an inverter.

18. A battery management system to manage a battery, comprising:

a resistor configured to be selectively coupled in series

between the battery and a first power source, and

between an external source and the first power source;

a switch coupled between one end of the resistor and the first power source; and

a main control unit for measuring an internal resistance of the battery by selectively coupling the resistor in series

between the battery and the first power source when discharging the battery to the external source, and

between the external source and the first power source when charging the battery from the external source, by selectively turning on the switch.

19. The battery management system of claim 18, wherein the main control unit is configured to measure the internal resistance of the battery by using the following equation:

20. A driving method to drive a battery management system that manages a battery, the driving method comprising:

selectively coupling a resistor in series

between the battery and a first power source, and

between an external source and the first power source, by using a switch coupled between one end of the resistor and the first power source; and

calculating an internal resistance of the battery,

wherein when measuring the internal resistance of the battery, the resistor is selectively coupled in series

between the battery and a first power source when discharging the battery to the external source, and

between the external source and the first power source when charging the battery from the external source, by selectively turning on the switch.

21. The driving method of claim 20, wherein the calculating of the internal resistance of the battery comprises using the equation: