Apparatus, system, and method of preventing battery rack damage by measuring current

• US 9,373,973 B2
• Filed: 11/12/2014
• Issued: 06/21/2016
• Est. Priority Date: 02/20/2014
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Lee, Jongbum
• Primary Examiner(s): Rodas, Richard Isla
• Assistant Examiner(s): SHARIEF, MOHAMMED JAMEEL
• Application Number:
  US14/649,323
• Publication Number:
  US 20160020629A1
• Time in Patent Office: 587 Days
• Field of Search: 320/164, 307/77
• US Class Current: 1/1
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02H 11/005 in case of too low isolation resistance, too high load, short-circuit; earth fault
• CPC Class Codes: H02H 7/18 for batteries; for accumulators
• CPC Class Codes: H02J 7/00718 in response to charge current gradient
• 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

The present invention relates to an apparatus, a system, and a method of preventing a battery rack from being damaged by measuring a current, which, when a battery module is abnormally connected with a relay in some battery racks in installing the relay, which conducts or blocks a current flowing in the battery rack including a plurality of battery modules so that a current exceeding a predetermined current limit value flows in the battery rack, prevent a short-circuit phenomenon, by controlling an operation state of the relay before the battery rack and the relay form a short circuit, and prevent capacitance imbalance between the battery racks by controlling an operation state of the relay when a voltage difference between a plurality of battery racks exceeds a predetermined voltage difference.

Claims

1. An apparatus for preventing a battery rack from being damaged by measuring a current, comprising:

a current measuring unit configured to measure a current value of a battery rack including a plurality of battery modules;

a current comparing unit configured to compare whether the current value measured by the current measuring unit is greater or smaller than a predetermined current limit value;

a relay controller configured to control operation states of a precharge relay and a main relay based on the comparison result value obtained by the current comparing unit before the operation state of the main relay is changed from an off state to an on state after the operation state of the precharge relay is changed to the on state; and

a voltage measuring unit configured to measure a voltage value of the battery rack,

wherein the apparatus for preventing a battery rack from being damaged by measuring a current is provided in one or more battery racks each, and individually performs, on a corresponding battery rack, a process of measuring a current value of the corresponding battery rack, comparing the measured current value with a predetermined current limit value, and controlling operation states of a precharge relay and a main relay of the corresponding battery rack according to a result of the comparison, and a process of measuring a voltage value of the corresponding battery rack.

2. The apparatus of claim 1, wherein the precharge relay is serially connected with a precharge resistor, of which a resistance value is determined according to a capacity of the battery rack, to decrease a current value of an overcurrent flowing in the battery rack.

3. The apparatus of claim 1, wherein the current measuring unit measures a current value of a current flowing in the battery rack and transmits the measured current value to the current comparing unit, and includes a current sensor corresponding to one or more of a current transformer method, a hall element method, and a fuse method.

4. The apparatus of claim 1, wherein when the current value received from the current measuring unit exceeds the predetermined current limit value, the current comparing unit transmits a current exceeding signal to the relay controller.

5. The apparatus of claim 4, wherein when the relay controller receives the current exceeding signal from the current comparing unit, the relay controller changes the operation state of the precharge relay from the on state to the off state, and maintains the operation state of the main relay in the off state.

6. The apparatus of claim 1, further comprising:

a voltage comparing unit connected with the voltage measuring unit, which measures a voltage of a plurality of battery racks each, and configured to calculate a difference between the plurality of voltage values measured by the voltage measuring unit.

7. The apparatus of claim 6, wherein when the result value exceeding a predetermined voltage allowance difference is calculated among the result values obtained by calculating the difference between the plurality of voltage values, the voltage comparing unit transmits a voltage imbalance signal to a relay controller of a corresponding battery rack.

8. The apparatus of claim 7, wherein when the relay controller receives the voltage imbalance signal from the voltage comparing unit, the relay controller changes the operation states of the precharge relay and the main relay from the on state to the off state.

9. The apparatus of claim 1, wherein the apparatus is included in a battery management system (BMS) for controlling the one or more battery racks.

18. The system of claim 1, wherein the system is included in a battery management system for controlling the one or more battery racks.

10. A system for preventing a battery rack from being damaged by measuring a current, comprising:

an apparatus for preventing a battery rack from being damaged by measuring a current in one or more battery racks each, the apparatus for preventing a battery rack from being damaged by measuring a current, comprising;

a current measuring unit configured to measure a current value of a battery rack including a plurality of battery modules;

a current comparing unit configured to compare whether the current value measured by the current measuring unit is greater or smaller than a predetermined current limit value;

a relay controller configured to control operation states of a precharge relay and a main relay based on the comparison result value obtained by the current comparing unit before the operation state of the main relay is changed from an off state to an on state after the operation state of the precharge relay is changed to the on state; and

a voltage measuring unit configured to measure a voltage value of the battery rack,

wherein the system for preventing a battery rack from being damaged by measuring a current individually performs, on a corresponding battery rack, a process of measuring a current value of the corresponding battery rack, comparing the measured current value with a predetermined current limit value, and controlling operation states of a precharge relay and a main relay of the corresponding battery rack according to a result of the comparison, and a process of measuring a voltage value of the corresponding battery rack.

11. The system of claim 10, wherein the precharge relay is serially connected with a precharge resistor, of which a resistance value is determined according to a capacity of the battery rack, to decrease a current value of an overcurrent flowing in the battery rack.

12. The system of claim 10, wherein the current measuring unit measures a current value of a current flowing in the battery rack and transmits the measured current value to the current comparing unit, and includes a current sensor corresponding to one or more of a current transformer method, a hall element method, and a fuse method.

13. The system of claim 10, wherein when the current value received from the current measuring unit exceeds the predetermined current limit value, the current comparing unit transmits a current exceeding signal to the relay controller.

14. The system of claim 13, wherein when the relay controller receives the current exceeding signal from the current comparing unit, the relay controller changes the operation state of the precharge relay from the on state to the off state, and maintains the operation state of the main relay in the off state.

15. The system of claim 10, further comprising:

a voltage comparing unit connected with the voltage measuring unit, which measures a voltage of a plurality of battery racks each, and configured to calculate a difference between the plurality of voltage values measured by the voltage measuring unit.

16. The system of claim 15, wherein when the result value exceeding a predetermined voltage allowance difference is calculated among the result values obtained by calculating the difference between the plurality of voltage values, the voltage comparing unit transmits a voltage imbalance signal to a relay controller of a corresponding battery rack.

17. The system of claim 16, wherein when the relay controller receives the voltage imbalance signal from the voltage comparing unit, the relay controller changes the operation states of the precharge relay and the main relay from the on state to the off state.

19. A method of preventing a battery rack from being damaged by measuring a current, comprising:

(a) providing an apparatus for preventing a battery rack from being damaged by measuring a current, which includes a current measuring unit, a current comparing unit, a relay controller, and a voltage measuring unit, in one or more battery racks each;

(b) individually performing, by the apparatus, on a corresponding battery rack, a process of measuring a current value of the corresponding battery rack, comparing the measured current value with a predetermined current limit value, and controlling operation states of a precharge relay and a main relay of the corresponding battery rack according to a result of the comparison, and a process of measuring a voltage value of the corresponding battery rack;

(c) providing a voltage comparing unit connected with the voltage measuring unit for measuring a voltage of the plurality of battery racks each; and

(d) receiving a voltage value of the plurality of battery racks, calculating a difference between the plurality of voltage values, and controlling operation states of a precharge relay and a main relay of a corresponding battery rack according to a result of the calculation,

wherein (b) includes;

(b1) measuring, by the current measuring unit, a current value of a battery rack including a plurality of battery modules;

(b2) comparing, by the current comparing unit, whether the current value measured by the current measuring unit is greater or smaller than a predetermined current limit value;

(b3) controlling, by the relay controller, the operation states of the precharge relay and the main relay based on the comparison result value obtained by the current comparing unit before the operation state of the main relay is changed from an off state to an on state after the operation state of the precharge relay is changed to the on state; and

(b4) measuring, by the voltage measuring unit, a voltage value of the battery rack.

20. The method of claim 19, wherein (b1) includes measuring, by the current measuring unit, a current value of a current flowing in the battery rack, and transmitting the measured current value to the current comparing unit.

21. The method of claim 19, wherein (b2) includes, when the current value received from the current measuring unit exceeds the predetermined current limit value, transmitting, by the current comparing unit, a current exceeding signal to the relay controller.

22. The method of claim 19, wherein (b3) includes, when the relay controller receives the current exceeding signal from the current comparing unit, changing, by the relay controller, the operation state of the precharge relay from the on state to the off state, and maintaining the operation state of the main relay in the off state.

23. The method of claim 19, wherein (d) includes calculating, by the voltage comparing unit, a difference between a plurality of voltage values measured by the voltage measuring unit, and transmitting a voltage imbalance signal to the relay controller when the result value exceeding a predetermined voltage allowance difference is calculated among the calculated result values.

24. The method of claim 23, wherein (d) further includes changing, by the relay controller, the operation states of the precharge relay and the main relay from the on state to the off state when the relay controller receives the voltage imbalance signal from the voltage comparing unit.