US 12,263,757 B2
Battery equalization system and methods of using same including first and second power supply branch circuits
Hongbin Luo, Shenzhen (CN); Chao Wang, Shenzhen (CN); Xiaofeng Shen, Shenzhen (CN); and Qiuyong Zeng, Shenzhen (CN)
Assigned to BYD COMPANY LIMITED, Shenzhen (CN)
Filed by BYD COMPANY LIMITED, Guangdong (CN)
Filed on Jun. 21, 2023, as Appl. No. 18/338,936.
Application 18/338,936 is a continuation of application No. 16/642,718, abandoned, previously published as PCT/CN2018/103683, filed on Aug. 31, 2018.
Claims priority of application No. 201710773473.9 (CN), filed on Aug. 31, 2017.
Prior Publication US 2023/0356626 A1, Nov. 9, 2023
Int. Cl. B60L 58/22 (2019.01); B60L 58/18 (2019.01); B60L 58/20 (2019.01); H02J 7/00 (2006.01)
CPC B60L 58/22 (2019.02) [B60L 58/18 (2019.02); B60L 58/20 (2019.02); H02J 7/00 (2013.01); H02J 7/0013 (2013.01); H02J 7/0014 (2013.01); H02J 7/0016 (2013.01); H02J 7/0019 (2013.01); H02J 7/0047 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A battery equalization system, comprising:
a collection circuit, configured to collect parameter information of cells in a battery pack;
an equalization circuit, configured to perform equalization processing on the cells in the battery pack;
a controller, connected to the collection circuit and the equalization circuit separately, and configured to determine, according to the parameter information of the cells in the battery pack, whether there is a cell in the battery pack needs enabling of equalization, and to control, when it is determined that a cell in the battery pack needs enabling of equalization, the equalization circuit to perform the equalization processing on the cell that needs enabling of equalization; wherein the controller is connected to the collection circuit and the equalization circuit corresponding to the cell that needs enabling of equalization through one channel, and the collection circuit and the equalization circuit are configured to multiplex the channel in a time division manner such that collection of parameter information of the cell that needs enabling of equalization is separated from the equalization processing of the cell that needs enabling of equalization; wherein a process of enabling of equalization comprises:
detecting a first cell of the cells with a smallest voltage value,
detecting a second cell of the cells with a voltage value greater than the smallest voltage value,
calculating a voltage difference for the second cell by subtracting the voltage value by the smallest voltage value,
determining the voltage difference is greater than or equal to a preset voltage difference threshold, and
performing the equalization processing on the second cell until the voltage difference is less than the preset voltage difference threshold;
a power supply branch circuit, controlled by the controller to connect a power supply unit to the battery equalization system when the battery pack stops charging or discharging and a cell needs enabling of equalization, so that the power supply unit supplies power to the battery equalization system; wherein the power supply branch circuit comprises:
a first power supply branch circuit connected to the power supply unit and the battery equalization system; the first power supply branch circuit is configured to supply power to the battery equalization system and loads of a vehicle except the battery equalization system; and
a second power supply branch circuit connected to the power supply unit and the battery equalization system; the second power supply branch circuit is configured to supply power to the battery equalization system;
the second power supply branch circuit is in a connected state, and the first power supply branch circuit is in a disconnected state under the control of a vehicle body controller when the battery pack stops charging or discharging and the cell needs enabling of equalization.