BATTERY SYSTEM

• US 20170054134A1
• Filed: 08/11/2016
• Published: 02/23/2017
• Est. Priority Date: 08/20/2015
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: CHOI, Jongrock, PARK, Jeongkurn, KIM, Junyoung, SON, Cheolgi, KIM, Hwasu, PARK, Sujun, KIM, Dongrak, YOO, Kwangmin, DO, Hyunjun, SONG, Inseob
• Granted Patent: US 10,347,952 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/36 Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A battery system includes a first battery, a second battery, and a battery manager. The first battery is electrically connected between a first node and a second node via a first module switch in a short circuit state. The second battery is electrically insulated from the first battery by a second module switch in an open circuit state. The battery manager detects a first battery voltage of the first battery, a second battery voltage of the second battery, and a system current flowing between the first and second nodes, determines an open circuit voltage of the first battery based on the first battery voltage and the system current, and short-circuits the second module switch when the open circuit voltage is substantially equal to the second battery voltage so that the at least one second battery is connected to the at least one first battery in parallel.

Claims

1. A battery system, comprising:

a first battery electrically connected between a first node and a second node via a first module switch in a short circuit state;

a second battery electrically insulated from the first battery by a second module switch in an open circuit state; and

a battery manager to detect a first battery voltage of the first battery, a second battery voltage of the second battery, and a system current flowing between the first and second nodes, to determine an open circuit voltage of the first battery based on the first battery voltage and the system current, and to short-circuit the second module switch when the open circuit voltage is substantially equal to the second battery voltage so that the at least one second battery is connected to the at least one first battery in parallel.

2. The battery system as claimed in claim 1, wherein the battery manager is to connect the second battery to the first battery in parallel while the first battery is being charged or discharged.

3. The battery system as claimed in claim 1, wherein:

when the first battery is being discharged, the battery manager is to control the second module switch to short-circuit when the first battery voltage is lower than the second battery voltage by an estimated value.

4. The battery system as claimed in claim 1, wherein:

when the first battery is being charged, the battery manager is to control the second module switch to short-circuit when the first battery voltage is higher than the second battery voltage by an estimated value.

5. The battery system as claimed in claim 3, wherein the battery manager is to:

store information corresponding to an internal resistance value of the first battery, and

determine the estimated value to be a product of the system current and the internal resistance value of the first battery.

6. The battery system as claimed in claim 1, wherein the battery manager is to estimate the open circuit voltage of the first battery based on an inclination of a variation in the first battery voltage with respect to a variation in the system current.

7. The battery system as claimed in claim 1, further comprising:

a system switch connected between the first node and an external terminal, wherein the battery manager is to open the system switch when a discharge current discharged from the first battery is greater than a discharge reference value and is to open the first module switch when a charge current introduced into the first battery is greater than a charge reference value.

8. A battery system, comprising:

a plurality of battery modules selectively connected to one another in parallel; and

a system manager to manage the battery modules, wherein each of the battery modules includes;

a module switch serially connected to a battery between a pair of module terminals, and

a module manager to detect a battery voltage and a battery current of the battery, to transmit information corresponding to the battery voltage and the battery current to the system manager, and to switch the module switch under control of the system manager, and

wherein the system manager is to determine a timing to short-circuit a module switch of at least one remaining second battery module from among the battery modules based on the battery voltage and the battery current of each of the battery modules, while at least one first battery module from among the battery modules is being charged or discharged.

9. The battery system as claimed in claim 8, wherein the system manager is to:

determine an open circuit voltage of the first battery module based on the battery voltage and the battery current of the first battery module, and

transmit a switch short-circuit command to a module management unit of the second battery module when the open circuit voltage is substantially equal to the battery voltage of the second battery module.

10. The battery system as claimed in claim 9, wherein the system manager is to:

determine an internal resistance value of the first battery module based on a ratio of a variation in the battery voltage of the first battery module to a variation in the battery current of the first battery module, and

determine the open circuit voltage of the first battery module based on the battery voltage, the battery current, and the internal resistance value of the first battery module.

11. The battery system as claimed in claim 10, wherein:

while the first battery module is being discharged, the system manager is to determine the open circuit voltage by adding a product of the battery current and the internal resistance value of the first battery module to the battery voltage of the first battery module, and

while the first battery module is being charged, the system manager is to determine the open circuit voltage by subtracting the product of the battery current and the internal resistance value of the first battery module from the battery voltage of the first battery module.

12. The battery system as claimed in claim 9, wherein the system manager is to:

store information corresponding to a relationship between a state of charge (SOC) of the first battery module and the open circuit voltage of the first battery module,

calculate the SOC of the first battery module by accumulating the battery current of the first battery module, and

estimate the open circuit voltage of the first battery module based on the SOC of the first battery module.

13. An apparatus, comprising:

a detector to detect a first battery voltage of a first battery, a second battery voltage of a second battery, and current flowing between first and second nodes, the first battery connected between a first node and a second node when a first module switch is in a short circuit state, the second battery electrically insulated from the first battery when a second module switch in an open circuit state; and

a battery manager to determine an open circuit voltage of the first battery based on the first battery voltage and the current and to short-circuit the second module switch when the open circuit voltage is substantially equal to the second battery voltage to connect the second battery to the first battery in parallel.

14. The apparatus as claimed in claim 13, wherein the battery manager is to connect the second battery to the first battery in parallel while the first battery is being charged or discharged.

15. The apparatus as claimed in claim 13, wherein the battery manager is to control the second module switch to short-circuit when the first battery voltage is lower than the second battery voltage by an estimated value during a time when the first battery is being discharged.

16. The apparatus as claimed in claim 13, wherein the battery manager is to control the second module switch to short-circuit when the first battery voltage is higher than the second battery voltage by an estimated value during a time when the first battery is being charged.

17. The apparatus as claimed in claim 16, wherein the battery manager is to:

store information corresponding to an internal resistance value of the first battery, and

determine the estimated value to be a product of the system current and the internal resistance value of the first battery.