US 12,272,973 B2
Energy storage system and method for controlling energy storage system
Jianshan Li, Shanghai (CN); He Zhou, Shanghai (CN); Shijiang Yu, Shanghai (CN); and Zhipeng Wu, Shenzhen (CN)
Assigned to Huawei Digital Power Technologies Co., Ltd., Shenzhen (CN)
Filed by Huawei Digital Power Technologies Co., Ltd., Shenzhen (CN)
Filed on Apr. 12, 2022, as Appl. No. 17/719,130.
Claims priority of application No. 202110388542.0 (CN), filed on Apr. 12, 2021.
Prior Publication US 2022/0329082 A1, Oct. 13, 2022
Int. Cl. H02J 7/00 (2006.01)
CPC H02J 7/0019 (2013.01) [H02J 7/0047 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An energy storage device comprising:
a battery string, comprising a plurality of battery cells;
a plurality of balancing controllers, which are in a one-to-one correspondence with the plurality of battery cells, and are configured to control state of charge balance between the battery cells;
wherein each battery cell is connected in parallel to an input end of a balancing controller associated with the battery cell, output ends of the plurality of balancing controllers are connected in parallel, positive output ends of the plurality of balancing controllers are connected to a positive balancing bus, negative output ends of the plurality of balancing controllers are connected to a negative balancing bus;
a voltage converter, configured to perform voltage conversion, wherein a positive input end of the voltage converter is connected to a positive electrode of the battery string by using a battery bus, and a negative input end and a negative output end of the voltage converter are grounded;
a first switch, disposed between the positive electrode of the battery string and the positive input end of the voltage converter;
a second switch, disposed between the positive balancing bus and the positive input end of the voltage converter; and
a controller, configured to: control the first switch to be closed and the second switch to be open, to enable the voltage converter to receive a voltage by using the battery bus; or control the first switch to be open and the second switch to be closed, to enable the voltage converter to receive a voltage by using the positive balancing bus.