Battery management system and battery management method

• US 20070090798A1
• Filed: 10/19/2006
• Published: 04/26/2007
• Est. Priority Date: 10/20/2005
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Seo, Se-Wook, Lim, Gye-Jong, Yun, Han-Seok
• Granted Patent: US 7,880,432 B2
• Time in Patent Office: Days
• US Class Current: 320/116
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/0038 relating to sensors
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60L 58/26 by cooling
• 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: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The battery management system of the present invention measures a cell voltage of a battery more efficiently using a small number of elements, and measures a pack current and voltage thereof when measuring the voltages of a plurality of cells. The battery management system is coupled to the battery formed with one pack having a plurality of battery cells. The battery includes a first sub-pack having first and second batteries among the plurality of battery cells. The battery management system includes first to fourth relays and an A/D converter. The first and the second relays transmit the cell voltages in response to respective first and second control signals by being coupled to each output terminal of the first and second battery cells of the first sub-pack. The third relay transmits the cell voltage transmitted though one of the first and second relays in response to a third control signal, and the first charging unit stores the cell voltage transmitted from the third relay. The fourth relay transmits the cell voltage stored in the first charging unit in response to a fourth control signal. The A/D converter converts the cell voltages transmitted through the fourth relay into digital data.

Claims

1. A battery management system coupled to a battery in which a plurality of battery cells are formed as one pack, wherein the battery includes a first sub-pack having first and second battery cells among the plurality of battery cells, said battery management system comprising:

first and second relays coupled to respective output terminals of the first and second battery cells of the first sub-pack for transmitting cell voltages to the same in response to respective first and second control signals;

a third relay for transmitting the cell voltage received through one of the first and second relays in response to a third control signal;

a first charging unit for storing the cell voltage transmitted from the third relay;

a fourth relay for transmitting the cell voltage stored in the first charging unit in response to a fourth control signal; and

,

an A/D converter for converting the transmitted cell voltage of the fourth relay into digital data.

2. The battery management system of claim 1, wherein the battery further includes a second sub-pack having third and fourth battery cells among the plurality of battery cells, battery management system further comprising:

fifth and sixth relays coupled to respective output terminals of the third and fourth battery cells of the second sub-pack and for transmitting cell voltages to the same in response to the respective first and second control signals;

a seventh relay for transmitting the transmitted cell voltage of any one of the fifth and sixth relays in response to the third control signal;

a second charging unit for storing the cell voltage transmitted from the seventh relay; and

an eighth relay for transmitting the stored cell voltage of the second charging unit in response to the fourth control signal;

wherein the A/D converter converts the cell voltages transmitted through the eighth relay into digital data.

3. The battery management system of claim 2, wherein:

the A/D converter converts the cell voltage of the first battery cell of the first sub-pack transmitted through the fourth relay, and the cell voltage of the third battery cell of the second sub-pack transmitted through the eighth relay, into digital data; and

the A/D converter converts the cell voltage of the second battery cell of the first sub-pack transmitted through the fourth relay, and the cell voltage of the fourth battery cell of the second sub-pack transmitted through the eighth relay, into digital data.

4. The battery management system of claim 2, wherein the third control signal is given as an on-signal when the first and second control signals are given as an on-signal.

5. The battery management system of claim 3, wherein

the fourth control signal is given as an on-signal when the third control signal is given as an off-signal.

6. The battery management system of claim 3, wherein the fourth control signal is given as an on-signal when the first and second control signals are given as an off-signal.

7. A battery management system, comprising:

a battery including first, second, and third sub-packs having first and second battery cells, respectively, among a plurality of battery cells;

a pack voltage measurer for measuring a pack voltage of the battery;

a pack current measurer for measuring a pack current of the battery;

a cell voltage measurer for respectively measuring cell voltages of the plurality of battery cells; and

an A/D converter including first, second, and third input terminals for receiving the outputs of the cell voltage measurer, a fourth input terminal for receiving the output of the pack voltage measurer, and a fifth input terminal for receiving the output of the pack current measurer, and for sequentially converting the input signals of the first, second, third, fourth, and fifth input terminals into digital data;

wherein the cell voltage measurer comprises;

a first charging unit for storing a cell voltage of any one of the first and second battery cells of the first sub-pack;

a second charging unit for storing a cell voltage of one of the first and second battery cells of the second sub-pack;

a third charging unit for storing a cell voltage of one of the first and second battery cells of the third sub-pack; and

first, second, and third relays for transmitting the stored cell voltages of the first, second, and third charging units to the first, second, and third input terminals of the A/D converter in response to a first control signal.

8. The battery management system of claim 7, wherein the cell voltage measurer comprises:

fourth and fifth relays for transmitting the cell voltages by being coupled to each output terminal of the first and second battery cells of the first sub-pack in response to the respective second and third control signals;

a sixth relay for transmitting the cell voltage transmitted through one of the fourth and fifth relays in response to a fourth control signal to the first charging unit;

seventh and eighth relays for transmitting the cell voltages by being coupled to each output terminal of the first and second battery cells of the second sub-pack in response to the respective second and third control signals;

a ninth relay for transmitting the cell voltage transmitted through one of the seventh and eighth relays in response to the fourth control signal to the second charging unit;

tenth and eleventh relays for transmitting the cell voltages by being coupled to each output terminal of the first and second battery cells of the third sub-pack in response to the respective second and third control signals; and

a twelfth relay for transmitting the cell voltage transmitted through one of the tenth and eleventh relays in response to the fourth control signal to the third charging unit.

9. The battery management system of claim 8, wherein the fourth control signal is given as an on-signal when the second and third control signals are respectively given as an on-signal, and

wherein the first control signal is given as an off-signal when the fourth control signal is given as an off-signal.

10. The battery management system of claim 9, wherein the A/D converter sequentially outputs the converted digital signals using one output terminal thereof.

11. The battery management system of claim 9, wherein the A/D converter comprises at least four output terminals;

and

wherein the A/D converter converts the input data of the first, second, fourth, and fifth input terminals into digital data and outputs the converted data using the respective four output terminals thereof.

12. A driving method for a battery management system which includes at least one pack having a plurality of cells, the driving method comprising:

a) measuring a voltage of at least one cell among the plurality of cells;

b) measuring a voltage and a current of the pack;

c) measuring a voltage of at least one cell among the plurality of cells except said at least one cell for which the voltage is already measured; and

d) again measuring the voltage and the current of the pack.

13. A driving method of a battery management system in which the battery is formed with one pack having at least N×

M battery cells (where N is a natural number and M is a natural number greater than

     3), the driving method comprising the steps of;

a) measuring a cell voltage of an (N+1)-th battery cell;

b) measuring a cell voltage of a (2N+1)-th battery cell;

c) measuring a pack voltage and current of the battery; and

d) measuring a cell voltage of a (3N+1)-th battery cell.

14. A driving method of a battery management system in which the battery is formed with one pack having at least N×

M battery cells (where N is a natural number and M is a natural number greater than

     3), the driving method comprising;

a) charging first, second, and third charging units with cell voltages of (N+1)-th, (2N+1)-th, and (3N+1)-th battery cells, respectively;

b) measuring the cell voltage of the (N+1)-th battery cell based on the charged voltage of the first charging unit;

c) measuring the cell voltage of the (2N+1)-th battery cell based on the charged voltage of the second charging unit;

d) measuring a pack voltage and current of the battery; and

e) measuring the cell voltage of the (3N+1)-th battery cell based on the charged voltage of the third charging unit.