System and method for cell balancing of battery pack

• US 9,067,505 B2
• Filed: 12/16/2013
• Issued: 06/30/2015
• Est. Priority Date: 05/03/2013
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group), Kia Motors Corporation (Kia Corp.)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group), Kia Motors Corporation (Kia Corp.)
• Inventors: Jeong, Wooyeol
• Primary Examiner(s): Edwards, Jerrah
• Assistant Examiner(s): WEBER, TAMARA L
• Application Number:
  US14/107,542
• Publication Number:
  US 20140330463A1
• Time in Patent Office: 561 Days
• Field of Search: 701/22
• US Class Current: 1/1
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• 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

A system and method of cell balancing of a battery pack using a cell balancing device of a battery pack is provided and includes a controller that detects an inter-cell voltage deviation in the battery pack. In addition, the controller is configured to determine whether to perform cell balancing on the battery pack and inactivate a relay connected with the battery pack. The controller is further configured to perform cell balancing in the battery pack.

Claims

1. A method of cell balancing of a battery pack, using a cell balancing device of a battery pack, the method comprising:

detecting, by a controller, an inter-cell voltage deviation in the battery pack;

determining, by the controller, whether to perform cell balancing on the battery pack by comparing a magnitude of a control signal to a predetermined limit;

inactivating, by the controller, a relay connected with the battery pack; and

performing, by the controller, cell balancing in the battery pack.

2. The method of claim 1, wherein the determining of whether to perform cell balancing includes:

determining, by the controller, whether to perform cell balancing by comparing the detected voltage deviation with a stored threshold value.

3. The method of claim 1, wherein the inactivating of the relay includes:

determining, by the controller, whether to inactivate some battery packs by checking the charge and discharge amounts of the battery packs based on traveling of a vehicle.

4. A method of cell balancing of a battery pack, using a cell balancing device of a battery pack, the method comprising:

detecting, by a controller, an inter-cell voltage deviation in a battery pack;

determining, by the controller, a battery pack that requires cell balancing, using the detected voltage deviation;

inactivating, by the controller, a relay connected with the determined battery pack and restricting charge and discharge of the determined battery pack;

performing, by the controller, cell balancing on the cells in the determined battery pack; and

connecting, by the controller, the relay and returning to a basic mode when a magnitude of a control signal is greater than a predeterminded limit,

wherein the magnitude of the control signal is greater than the predetermined limit when an acceleration pedal is engaged over a threshold value and a requested output of an engine is greater than a predetermined engine output limit.

5. The method of claim 4, wherein the magnitude of the control signal is greater than the predetermined limit when a current value input by regenerative braking of a motor is greater than a predetermined current value limit during braking of a vehicle.

6. The method of claim 4, wherein the magnitude of the control signal is greater than the predetermined limit when a heater or an air conditioner is required to operate and a room temperature is beyond a threshold value range.

7. A system for cell balancing of a battery pack, comprising:

a plurality of battery packs having a plurality of cells and connected in parallel;

a relay connected between the battery packs; and

a battery management system executed by a controller to determine whether to perform cell balancing on the battery pack based on an inter-cell voltage deviation of the battery pack and to connecting the relay and return to a basic mode when a magnitude of a control signal is greater than a predeterminded limit,

wherein the magnitude of the control signal is greater than the predetermined limit when an acceleration pedal is engaged over a threshold value and a requested output of an engine is greater than a predetermined engine output limit, or when a current value input by regenerative braking of a motor is greater than a predetermined current value limit during braking of a vehicle.

8. The method of claim 7, wherein the battery management system includes one or more sub-battery management systems connected with the battery packs, respectively, and configured to detect an inter-cell voltage deviation of the battery packs, and perform cell balancing by inactivating the relays when the voltage deviation is equal to or greater than a threshold value.

9. The system of claim 7, wherein the magnitude of the control signal is greater than the predetermined limit when a heater or an air conditioner is required to operate a room temperature is beyond a predetermined threshold value range.