BATTERY MANAGEMENT SYSTEM AND DRIVING METHOD THEREOF

• US 20080100298A1
• Filed: 09/13/2007
• Published: 05/01/2008
• Est. Priority Date: 11/01/2006
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: CHOI, Soo-Seok, LEE, Young-Jo, PARK, Ho-Young, KIM, Beom-Gyu, LIM, Gye-Jong, YUN, Han-Seok, TAE, Yong-Jun, SEO, Se-Wook
• Granted Patent: US 8,174,240 B2
• Time in Patent Office: Days
• US Class Current: 324/430
• 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; and

a first switch coupled to one end of the resistor,

wherein, when the battery management system calculates an internal resistance of a battery, the battery management system turns on the first switch to couple the battery with the resistor in parallel, and calculates the internal resistance of the battery by using a first current flowing to the resistor and a second current flowing to the battery.

2. The battery management system of claim 1, wherein the battery management system calculates the internal resistance of the battery by using the following equation:

$R_b=\frac{R_f\times <br><br>I_f}{I_c-I_f},$

where I_c denotes a charging and discharging current, If denotes a first current value of the first current, (I_c−

If) denotes a second current value of the second current, Rf denotes a resistance of the resistor, and Rb denotes the internal resistance of the battery.

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

a second switch coupled between the battery and an inverter in series, which transmits the charging and discharging current to and from the battery; and

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

4. 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.

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 3, 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 used in an electric or hybrid vehicle.

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

a resistor coupled to the battery in parallel;

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

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

a main control unit (MCU) to turn the first switch on and to calculate an internal resistance of the battery by using a second current flowing to the battery and 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;

a second switch coupled between the battery and an inverter, having a first end coupled to the first current sensor and a second end coupled to the second current sensor, which transmits current to and from the battery to charge and discharge the battery; and

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

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

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

12. The battery management system of claim 8, wherein the battery is used 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 to the battery in parallel;

measuring a second current flowing to the battery;

measuring a first current flowing to the resistor; and

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

14. The driving method of claim 13, wherein the selectively coupling of the resistor comprises coupling an end of the resistor opposite to that coupled to the battery with a first voltage during the calculating of the internal resistance.

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:

$R_b=\frac{R_f\times <br><br>I_f}{I_c-I_f},$

where I_c denotes a charging and discharging current, If denotes a first current value of the first current, (I_c−

If) denotes a second current value of the second current, Rf denotes a resistance of the resistor, and Rb denotes the internal resistance of the battery.

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; and

a main control unit which selectively connects the resistor to the battery in parallel when measuring an internal resistance of the battery.

19. The battery management system of claim 18, further comprising a switch coupled between one end of the resistor and one end of the battery, wherein the main control unit selectively connects the resistor to the battery in parallel by selectively turning on the switch.

20. The battery management system of claim 19, wherein the main control unit measures the internal resistance of the battery using the following equation:

$R_b=\frac{R_f\times <br><br>I_f}{I_c-I_f},$

where I_c denotes a charging and discharging current, If denotes a first current value of the first current which flows to the resistor Rf, (I_c−

If) denotes a second current value of the second current which flows to the battery, Rf denotes a resistance of the resistor, and Rb denotes the internal resistance of the battery.

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

selectively coupling a resistor to the battery in parallel; and

calculating an internal resistance of the battery, wherein the resistor is selectively coupled to the battery when measuring the internal resistance of the battery.

22. The driving method of claim 21, wherein the internal resistance is calculated using the equation:

$R_b=\frac{R_f\times <br><br>I_f}{I_c-I_f},$

where I_c denotes a charging and discharging current, If denotes a first current value of a first current which flows to the resistor Rf, (I_c−

If) denotes a second current value of a second current which flows to the battery, Rf denotes a resistance of the resistor, and Rb denotes the internal resistance of the battery.