US 12,081,048 B2
Apparatus and method for balancing battery packs connected in parallel
Su-Won Kang, Daejeon (KR); Han-Sol Kim, Daejeon (KR); Bum-Hee Lee, Daejeon (KR); and Sang-Ki Lee, Daejeon (KR)
Assigned to LG ENERGY SOLUTION, LTD., Seoul (KR)
Appl. No. 17/435,326
Filed by LG ENERGY SOLUTION, LTD., Seoul (KR)
PCT Filed Oct. 22, 2020, PCT No. PCT/KR2020/014528
§ 371(c)(1), (2) Date Aug. 31, 2021,
PCT Pub. No. WO2021/080358, PCT Pub. Date Apr. 29, 2021.
Claims priority of application No. 10-2019-0131694 (KR), filed on Oct. 22, 2019; and application No. 10-2020-0136984 (KR), filed on Oct. 21, 2020.
Prior Publication US 2022/0140620 A1, May 5, 2022
Int. Cl. H02J 7/00 (2006.01); B60L 58/22 (2019.01); G01R 31/3842 (2019.01); G01R 31/396 (2019.01); H01M 10/42 (2006.01)
CPC H02J 7/0016 (2013.01) [B60L 58/22 (2019.02); G01R 31/3842 (2019.01); G01R 31/396 (2019.01); H01M 10/425 (2013.01); H02J 7/007182 (2020.01); H01M 2010/4271 (2013.01); H01M 2220/20 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An apparatus for balancing battery packs connected in parallel, which is capable of complementarily performing pack balancing and cell balancing, the apparatus comprising:
first to nth battery packs connected in parallel with each other and respectively including a plurality of battery cells connected in series;
a voltage measurer configured to measure voltages of the plurality of battery cells included in each battery pack;
a plurality of discharge circuits connected in parallel to correspond to the plurality of battery cells; and
a processor operatively connected to the voltage measurer and the plurality of discharge circuits,
wherein the processor is configured to:
measure voltages of all battery cells included in each battery pack at a predetermined time interval by means of the voltage measurer, determine a pack voltage of each battery pack from the measured voltages of the battery cells, and determine a pack voltage deviation and a cell voltage deviation of each battery pack,
when the pack voltage deviation is greater than a first threshold value, determine a cell voltage corresponding to a preset criterion among the voltages of all battery cells included in the first to nth battery packs as a pack balancing target voltage, identify a battery cell having a higher voltage than the pack balancing target voltage among the battery cells included in each battery pack, and operate a discharge circuit connected to the identified battery cell to reduce the pack voltage deviation to the first threshold value or below, and
when the pack voltage deviation is equal to or smaller than the first threshold value among the first to nth battery packs, identify a battery pack having a cell voltage deviation greater than a second threshold value, determine a cell voltage corresponding to a preset criterion among the voltages of the battery cells included in the identified battery pack as a cell balancing target voltage for the identified battery pack, and operate a discharge circuit connected to a battery cell having a higher voltage than the cell balancing target voltage among the battery cells included in the identified battery pack to reduce the cell voltage deviation to the second threshold value or below.