BATTERY MANAGEMENT SYSTEM AND METHOD OF CONTROLLING THE SAME

• US 20130009648A1
• Filed: 07/02/2012
• Published: 01/10/2013
• Est. Priority Date: 07/04/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Samsung SDI Company Limited
• Original Assignee: SB LiMotive Co. Ltd (Samsung SDI Company Limited)
• Inventors: Tae, Yong-Jun
• Granted Patent: US 9,069,044 B2
• Time in Patent Office: Days
• US Class Current: 324/503
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00
• CPC Class Codes: G01R 31/007 using microprocessors or computers
• CPC Class Codes: G01R 31/3278 of relays, solenoids or reed switches measuring contact resistance G01R27/205; high voltage magnetic switches G01R31/3271, G01R31/333; testing electric windings G01R31/72; monitoring of fail safe circuits H01H47/002
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery

Abstract

A battery management system (BMS) and a method of controlling the BMS, which are capable of increasing reliability of determination of a defect of a relay by considering not only a voltage of a battery and a voltage of an inverter but also a current between the battery and the inverter and information regarding an operational state of the relay.

Claims

1. A battery management system (BMS), comprising:

a relay connected between a battery and an inverter;

a voltage determination unit connected to measure a voltage of the battery and a voltage of the inverter, in response to a signal corresponding to a state of the relay;

a current determination unit connected to measure a current flowing between the battery and the inverter, in response to the signal corresponding to the state of the relay; and

a relay defect determination unit disposed to determine a defect of the relay in dependence upon the current and a difference between the voltage of the battery and the voltage of the inverter.

2. The BMS of claim 1, wherein the relay comprises a positive main relay, a negative main relay, and an auxiliary relay.

3. The BMS of claim 1, wherein the relay defect determination unit determines whether a driving voltage of the relay is normal, and if normal, determines the defect of the relay according to the current and the difference between the voltage of the battery and the voltage of the inverter.

4. The BMS of claim 1, wherein the relay comprises a positive main relay, a negative main relay, and an auxiliary relay that is connected in parallel with the positive main relay.

5. The BMS of claim 1, wherein, according to a signal corresponding to an OFF state of the relay, the relay defect determination unit determines that the relay is defective when an absolute value of the current is greater than a first critical value, or the difference between the voltage of the battery and the voltage of the inverter is less than a second critical value.

6. The BMS of claim 5, wherein, according to a signal corresponding to an ON state of the auxiliary relay, the relay defect determination unit determines that the negative main relay is defective when an absolute value of the current flowing between the battery and the inverter is greater than the first critical value, or the difference between the voltage of the battery and the voltage of the inverter is less than the second critical value.

7. The BMS of claim 2, wherein, according to a signal corresponding to an ON state of the auxiliary relay, the relay defect determination unit determines a defect of the negative main relay based on the current flowing between the battery and the inverter, and the difference between the voltage of the battery and the voltage of the inverter.

8. The BMS of claim 2, wherein, according to a signal corresponding to an OFF state of the auxiliary relay arid a signal corresponding to an ON state of the negative main relay, the relay defect determination unit determines a defect of the auxiliary relay or a defect of the positive main relay based on the current flowing between the battery and the inverter, and the difference between the voltage of the battery and the voltage of the inverter.

9. The BMS of claim 8, wherein the relay defect determination unit determines that the auxiliary relay is defective when an absolute value of the current flowing between the battery and the inverter is greater than a first critical value and is less than a third critical value, and the difference between the voltage of the battery and the voltage of the inverter is less than a second critical value.

10. The BMS of claim 8, wherein the relay defect determination unit determines that the positive main relay and the auxiliary relay are defective when an absolute value of the current flowing between the battery and the inverter is greater than a third critical value, and the difference between the voltage of the battery and the voltage of the inverter is less than a second critical value.

11. The BMS of claim 1, wherein the signal corresponding to the state of the relay comprises a voltage of a coil that turns on or off the relay.

12. The BMS of claim 1, further comprising a communication unit for receiving the signal corresponding to the state of the relay from a vehicle control unit (VCU) that controls an ON or OFF state of the relay.

13. A battery management system (BMS), comprising:

a positive main relay, a negative main relay, and an auxiliary relay that are connected to a battery comprising at least one pack formed of a plurality of battery cells, the positive main relay, the negative main relay, and the auxiliary relay being connected between the battery and an inverter;

a voltage determination unit connected to measure a voltage of the battery and a voltage of the inverter, in response to a signal corresponding to a state of at least one relay from among the positive main relay, the negative main relay, and the auxiliary relay;

a current determination unit connected to measure a current flowing between the battery and the inverter, in response to the signal; and

a relay defect determination unit disposed to provide an indication of a defect of the at least one relay from among the positive main relay, the negative main relay, and the auxiliary relay in dependence upon the current and a difference between the voltage of the battery and the voltage of the inverter.

14. The BMS of claim 13, wherein, according to a signal corresponding to an OFF state of all of the positive main relay, the negative main relay, and the auxiliary relay, the relay defect determination unit determines that the at least one relay from among the positive main relay, the negative main relay, and the auxiliary relay is defective when an absolute value of the current is greater than a first critical value, or the difference between the voltage of the battery and the voltage of the inverter is less than a second critical value.

15. The BMS of claim 13, wherein, according to a signal corresponding to an ON state of the auxiliary relay, the relay defect determination unit determines that the negative main relay is defective when an absolute value of the current flowing between the battery and the inverter is greater than a first critical value, or the difference between the voltage of the battery and the voltage of the inverter is less than a second critical value.

16. The BMS of claim 13, wherein, according to a signal corresponding to an OFF state of the auxiliary relay and a signal corresponding to an ON state of the negative main relay, the relay defect determination unit determines that the auxiliary relay is defective when an absolute value of the current flowing between the battery and the inverter is greater than a first critical value and is less than a third critical value, and the difference between the voltage of the battery and the voltage of the inverter is less than a second critical value.

17. The BMS of claim 13, wherein, according to a signal corresponding to an OFF state of the auxiliary relay and a signal corresponding to an ON state of the negative main relay, the relay defect determination unit determines that the positive main relay and the auxiliary relay are defective when an absolute value of the current flowing between the battery and the inverter is greater than a third critical value, and the difference between the voltage of the battery and the voltage of the inverter is less than a second critical value.

18. The BMS of claim 16, wherein the first critical value is 1 ampere (A), the second critical value is a voltage value corresponding 2% of the voltage of the battery, and the third critical value is 27.7 A.