System For Controlling Voltage Balancing In a Plurality of Lithium-Ion Cell Battery Packs and Method Thereof

• US 20080303484A1
• Filed: 12/22/2005
• Published: 12/11/2008
• Est. Priority Date: 12/24/2004
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Lee, Han-Ho, Kim, Jee-Ho, Lee, Dal-Hoon, Yasuhito, Eguchi
• Granted Patent: US 7,638,973 B2
• Time in Patent Office: Days
• US Class Current: 320/134
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Disclosed is a system for adjusting a voltage balancing of cells in a lithium ion multicell battery pack. The system comprises a vertical interface outputting inputs of a reading balance signal defining a voltage reading period and a balance period and a reading hold signal holding a cell voltage when reading a voltage; an interface outputting an address clock for designating an address of a cell to be controlled and an input of a balance hold signal for independently reading a cell voltage within a voltage balance period; and a control section of a cell balancing adjusting circuit connected to the vertical interface and the interface and receiving signal outputs therefrom to adjust a balancing of cells.

Claims

1. A system for adjusting a voltage balancing of cells in a lithium ion multicell battery pack, the system comprising:

a vertical interface for outputting inputs of a reading balance signal defining a voltage reading period and a balance period and a reading hold signal holding a cell voltage when reading a voltage;

an interface for outputting an address clock for designating an address of a cell to be controlled and an input of a balance hold signal for independently reading a cell voltage within a voltage balance period; and

a control section of a cell balancing adjusting circuit connected to the vertical interface and the interface and for receiving signal outputs therefrom to adjust a balancing of cells.

2. The system according to claim 1, wherein the control section of the cell balancing adjusting circuit comprises an address counter for sequentially changing lines of the cells according to an address counter clock.

3. The system according to claim 1, further comprise a voltage detecting switch section for reading a voltage of one of the cells and a current switch section for supplying a balance current to one of the cells.

4. The system according to claim 1, wherein the control section turns off a balance current, determines a balance target value and decides to which cell the balance current is allowed to flow, during the voltage reading period.

5. The system according to claim 1, wherein the control section allows the balance current to flow the decided cell during the balance period.

6. The system according to claim 2, wherein the address counter produces a reset pulse by a time difference between the reading balance signal and the reading hold signal.

7. A method for adjusting a voltage balancing of cells in a lithium ion multicell battery pack, the method comprising the steps of:

defining a voltage reading period and a balance period according to a reading balance signal;

selecting each cell using an address counter clock and reading a voltage of the selected cell, during the voltage reading period;

determining a cell to which a balance current is allowed to flow, based on a balance target value; and

allowing the balance current to flow to the determined cell during the balance period.

8. The method according to claim 7, wherein the balance current flows to either a cell charge direction or cell discharge direction according to a comparison of the read voltage of the cell and the balance target value.

9. The method according to claim 7, wherein a hold of the cell voltage is performed after turning off the balance current based on the reading balance signal.

10. The method according to claim 7, wherein during the voltage reading period, the voltage of the selected cell is read after holding voltages of the cells, responsive to a reading hold signal.