Method, apparatus, and computer program for diagnosing internal short circuit of battery pack

1. A method of diagnosing an internal short circuit of a battery pack, based on a state of charge (SOC) variation amount and a balancing amount of each cell of the battery pack, the method comprising:

checking an SOC variation amount of the battery pack when the battery pack is in a first state;

checking a balancing amount of the battery pack, the balancing amount corresponding to a degree of balancing that is performed for a given period of time, or corresponding to an amount of charge consumed for balancing purposes, when the battery pack is in a second state;

determining whether the battery pack has an internal short circuit based on the checked SOC variation amount and the checked balancing amount; and

prior to the determining of whether the battery pack has an internal short circuit, calculating a first time period, which is a sum of all time periods during which the battery pack is in the first state, and a second time period, which is a sum of all time periods during which the battery pack is in the second state.

2. The method of claim 1 , wherein the first state corresponds to a rest state of the battery pack.

3. The method of claim 2 , wherein the checking of the SOC variation amount of the battery pack comprises:

selecting a cell from one or more cells in the battery pack, the selected cell having a largest SOC variation amount when the battery pack is in the first state; and

determining the SOC variation amount of the battery pack to correspond to the SOC variation amount of the selected cell.

4. The method of claim 3 , wherein the SOC variation amount of the battery pack corresponds to a difference between the SOC variation amount of the selected cell and an average of SOC variation amounts of the one or more cells.

5. The method of claim 1 , wherein the second state corresponds to an operation state of the battery pack.

6. The method of claim 5 , wherein the checking of the balancing amount of the battery pack comprises:

selecting a cell from at least two cells in the battery pack, the selected cell having a smallest balancing amount when the battery pack is in the second state; and

determining the balancing amount of the battery pack to correspond to the balancing amount of the selected cell.

7. The method of claim 6 , wherein the balancing amount of the battery pack corresponds to a difference between the balancing amount of the selected cell and an average of balancing amounts of the at least two cells.

8. The method of claim 5 , wherein the checking of the balancing amount of the battery pack comprises:

selecting a cell from at least two cells in the battery pack, the selected cell having a largest balancing amount when the battery pack is in the second state; and

determining the balancing amount of the battery pack to correspond to the balancing amount of the selected cell.

9. The method of claim 1 , further comprising determining the battery pack as having an internal short circuit when a sum of a first value obtained by multiplying the checked SOC variation amount by the first time period and a second value obtained by multiplying the checked balancing amount by the second time period is greater than a threshold value.

10. A computer program stored on a non-transitory medium for executing the method of claim 1 using a computer.

11. An apparatus for diagnosing an internal short circuit of a battery pack based on an SOC variation amount and a balancing amount of each cell of the battery pack, the apparatus comprising a controller that is configured to:

check an SOC variation amount of the battery pack when the battery pack is in a first state;

check a balancing amount of the battery pack when the battery pack is in a second state;

determine, based on the checked SOC variation amount and the checked balancing amount, whether the battery pack has an internal short circuit; and

calculate a first time period, which is a sum of all time periods during which the battery pack is in the first state, and a second time period, which is a sum of all time periods during which the battery pack is in the second state.

12. The apparatus of claim 11 , wherein the second state corresponds to an operation state of the battery pack, and

wherein the controller is further configured to:

select a cell from at least two cells in the battery pack, the selected cell having a smallest balancing amount when the battery pack is in the second state; and

determine the balancing amount of the battery pack to correspond to the balancing amount of the selected cell.

13. The apparatus of claim 12 , wherein the controller is further configured to determine the balancing amount of the battery pack to correspond to a difference between the balancing amount of the selected cell and an average of balancing amounts of the at least two cells.

14. The apparatus of claim 11 , wherein the second state corresponds to an operation state of the battery pack, and

wherein the controller is further configured to:

select a cell from at least two cells in the battery pack, the selected cell having a largest balancing amount when the battery pack is in the second state; and

determine the balancing amount of the battery pack to correspond to the balancing amount of the selected cell.

15. The apparatus of claim 12 , wherein the controller is further configured to determine that the battery pack has an internal short circuit when a sum of a first value obtained by multiplying the checked SOC variation amount by the first time period and a second value obtained by multiplying the checked balancing amount by the second time period is greater than a threshold value.

16. An apparatus for diagnosing an internal short circuit of a battery pack based on an SOC variation amount and a balancing amount of each cell of the battery pack, the apparatus comprising a controller that is configured to:

check an SOC variation amount of the battery pack when the battery pack is in a first state;

check a balancing amount of the battery pack when the battery pack is in a second state; and

determine, based on the checked SOC variation amount and the checked balancing amount, whether the battery pack has an internal short circuit,

wherein the first state corresponds to a rest state of the battery pack, and

wherein the controller is further configured to:

select one cell from one or more cells in the battery pack, the one cell having a largest SOC variation amount when the battery pack is in the first state; and

determine the SOC variation amount of the battery pack to correspond to the SOC variation amount of the selected cell.

17. The apparatus of claim 16 , wherein the controller is further configured to determine the SOC variation amount of the battery pack to correspond to a difference between the SOC variation amount of the selected cell and an average of SOC variation amounts of the one or more cells.