BATTERY SYSTEM, CONTROLLING METHOD OF THE SAME, AND POWER STORAGE SYSTEM INCLUDING THE BATTERY PACK

• US 20130207616A1
• Filed: 08/24/2012
• Published: 08/15/2013
• Est. Priority Date: 02/09/2012
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Shim, Kyung-Sub
• Granted Patent: US 9,088,164 B2
• Time in Patent Office: Days
• US Class Current: 320/136
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery system, a method of controlling the battery system, and an energy storage system including the battery system are disclosed. The method of controlling the battery system includes steps of selecting one of the plurality of batteries by using a multiplexer; measuring a voltage of the selected battery; and calculating a charging capacity of the battery based on the measured voltage. Accordingly, cell balancing may be efficiently performed.

Claims

1. A method of controlling a battery system comprising a plurality of batteries, the method comprising:

classifying batteries subject to cell balancing from the plurality of batteries;

selecting a battery from the plurality of batteries by using a multiplexer; and

when the battery selected by the multiplexer is subject to cell balancing, performing cell balancing on the selected battery.

2. The method of claim 1, further comprising:

measuring a voltage of the selected battery; and

calculating a charging capacity of the battery based on the sensed voltage.

3. The method of claim 2, wherein in the measure of the voltage of the selected battery, a capacitor is electrically connected to the multiplexer.

4. The method of claim 1, wherein the cell balancing comprises discharging the battery subject to cell balancing by using a single resistor.

5. The method of claim 1, wherein the multiplexer selects only the battery subject to cell balancing.

6. The method of claim 1, wherein the performance of cell balancing is controlled by using a switch.

7. The method of claim 1, wherein the battery subject to cell balancing has a charging capacity equal to or greater than a reference value.

8. The method of claim 7, wherein the cell balancing comprises discharging the battery subject to cell balancing such that the charging capacity of the battery subject to cell balancing reaches a charging capacity corresponding to the reference value.

9. The method of claim 7, wherein the reference value is 90% of an average of the charging capacities of the plurality of batteries.

10. A battery system, comprising:

a plurality of batteries;

a selection circuit unit comprising a multiplexer that selects a battery from the plurality of batteries;

a sensing circuit unit measuring a voltage of the selected battery;

a balancing circuit unit performing cell balancing on the selected battery if the selected battery is determined subject to cell balancing; and

a control unit controlling cell balancing by calculating charging capacities of the batteries based on the measured voltage of the plurality of batteries and classifying batteries subject to cell balancing.

11. The battery system of claim 10, wherein the control unit comprises:

a battery selecting unit selecting a battery by controlling the multiplexer;

a capacity measuring unit calculating a charging capacity of the battery based on the voltage of the battery selected by the multiplexer;

a reference value setting unit determining a charging capacity reference value based on the charging capacity calculated by the capacity measuring unit; and

a balancing control unit controlling cell balancing by classifying the batteries subject to cell balancing based on the calculated charging capacity and the determined charging capacity reference value.

12. The battery system of claim 11, wherein the cell balancing comprises discharging the battery subject to cell balancing by electrically connecting a single resistor to the battery.

13. The battery system of claim 11, wherein when performing the cell balancing, the multiplexer selects only the batteries subject to cell balancing.

14. The battery system of claim 11, wherein the cell balancing is controlled using a switch.

15. The battery system of claim 11, wherein the battery subject to cell balancing has a charging capacity equal to or greater than the charging capacity reference value.

16. The battery system of claim 15, wherein the cell balancing comprises discharging the battery subject to cell balancing such that the charging capacity of the battery subject to cell balancing reaches a charging capacity corresponding to the charging capacity reference value.

17. The battery system of claim 15, wherein the reference value is 90% of an average of charging capacities of the plurality of batteries.

18. An energy storage system comprising a battery system including a plurality of batteries and connecting the battery system to an external power source to supply power to a load, the energy storage system comprising:

a battery selecting unit that selects a battery by using a multiplexer;

a capacity measuring unit that measures a voltage of the battery selected by using the multiplexer and calculates a charging capacity of the battery based on the measured voltage;

a reference value setting unit that determines a charging capacity reference value based on the calculated charging capacity; and

a balancing control unit that classifies batteries subject to cell balancing based on the calculated charging capacity and the determined charging capacity reference value and performs cell balancing on the classified batteries.