BATTERY MANAGEMENT SYSTEM AND METHOD OF CONTROLLING THE SAME

• US 20120256599A1
• Filed: 02/14/2012
• Published: 10/11/2012
• Est. Priority Date: 04/07/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Samsung SDI Company Limited
• Original Assignee: SB LiMotive Co. Ltd (Samsung SDI Company Limited)
• Inventors: GU, Jae-Sung
• Granted Patent: US 9,170,305 B2
• Time in Patent Office: Days
• US Class Current: 320/149
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery management system (BMS) and a method of controlling the same are disclosed. In one embodiment, the BMS includes a reference setup unit configured to set a charge completion value used to calculate a state of health (SOH) of the battery, wherein the battery comprises one or more battery packs each including a plurality of battery cells, and a charge amount calculation unit configured to calculate an amount actually charged in the battery from a first point in time when charging of the battery begins to a second point in time when the battery charging actually reaches the charge completion value. The BMS may further include an SOH calculation unit configured to calculate the SOH of the battery based on a ratio of i) the actual charge amount to ii) a preset charge amount expected to be charged from the first time point to the second time point.

Claims

1. A battery management system (BMS) of an electric vehicle having a battery, the BMS comprising:

a reference setup unit configured to set a charge completion value used to calculate a state of health (SOH) of the battery, wherein the battery comprises one or more battery packs each including a plurality of battery cells;

a charge amount calculation unit configured to calculate an amount actually charged in the battery from a first point in time when charging of the battery begins to a second point in time when the battery charging actually reaches the charge completion value; and

an SOH calculation unit configured to calculate the SOH of the battery based on a ratio of i) the actual charge amount to ii) a preset charge amount expected to be charged from the first time point to the second time point.

2. The BMS of claim 1, wherein the charging of the battery comprises low-speed charging or high-speed charging.

3. The BMS of claim 1, wherein the charge completion value is a reference voltage of the battery.

4. The BMS of claim 3, wherein the reference voltage is a voltage of the battery when fully charged.

5. The BMS of claim 1, wherein the charge completion value is a state of charge (SOC) of the battery.

6. The BMS of claim 5, wherein the SOH is about 100% at the charge completion value.

7. The BMS of claim 1, wherein the SOH calculation unit calculates the SOH of the battery as represented in Equation 1.

8. The BMS of claim 1, further comprising a communication unit configured to communicate the state of the battery to a controller of the BMS based on the calculated SOH.

9. A method of controlling a battery management system (BMS) of an electric vehicle having a battery, the method comprising:

charging the battery, wherein the battery comprises one or more battery packs each including a plurality of battery cells;

calculating an amount actually charged in the battery from a first point in time when the charging of the battery begins to a second point in time when the battery charging actually reaches a charge completion value; and

calculating a state of health (SOH) of the battery based on a ratio of i) the actual charge amount to ii) a preset charge amount expected to be charged from the first time point to the second time point.

10. The method of claim 9, further comprising setting the charge completion value used to calculate the SOH of the battery.

11. The method of claim 9, further comprising estimating a distance to empty (DTE) of the vehicle based on the calculated SOH.

12. The method of claim 9, further comprising calculating a state of charge (SOC) of the battery based on the calculated SOH.

13. The method of claim 9, wherein the charge completion value is a reference voltage of the battery.

14. The method of claim 9, wherein the charge completion value is a value measured when the battery is initially used after being produced.

15. The method of claim 9, wherein the charge completion value is a value measured while the battery is being charged when the battery is initially used.

16. The method of claim 9, wherein the charge completion value is an SOC of the battery.

17. A battery management system (BMS) of an electric vehicle having a battery, the BMS comprising:

a reference setup device configured to set a charge completion value, wherein the battery comprises at least one battery pack;

a charge amount calculator configured to calculate an amount actually charged in the battery during a time period; and

an SOH calculator configured to calculate the SOH of the battery based on a ratio of i) the actual charge amount to ii) a preset charge amount expected to be charged during the time period.

18. The BMS of claim 17, wherein the time period is defined between a first point in time when charging of the battery begins and a second point in time when the battery charging actually reaches the charge completion value.

19. The BMS of claim 17, further comprising a communication unit configured to communicate the state of the battery to a controller of the BMS based on the calculated SOH.

20. The BMS of claim 17, wherein the SOH calculation unit calculates the SOH of the battery as represented in Equation 1.