US 12,451,691 B1
Method and system for sensitive equipment voltage sag control based on flexible multiplexing of energy storage system
Ying Wang, Chengdu (CN); Shuyuan Zhang, Chengdu (CN); Xianyong Xiao, Chengdu (CN); Shiru Jia, Chengdu (CN); Xinyue Wang, Chengdu (CN); Xuqing Tang, Chengdu (CN); and Xiaoyang Ma, Chengdu (CN)
Assigned to SICHUAN UNIVERSITY, Chengdu (CN)
Filed by SICHUAN UNIVERSITY, Sichuan (CN)
Filed on May 19, 2025, as Appl. No. 19/212,530.
Claims priority of application No. 202510159010.8 (CN), filed on Feb. 13, 2025.
Int. Cl. H02J 3/00 (2006.01); H02J 3/32 (2006.01); H02J 7/00 (2006.01); H02J 7/34 (2006.01)
CPC H02J 3/00125 (2020.01) [H02J 3/0012 (2020.01); H02J 3/32 (2013.01); H02J 7/00714 (2020.01); H02J 7/007182 (2020.01); H02J 7/342 (2020.01); H02J 7/345 (2013.01); H02J 3/003 (2020.01); H02J 2203/10 (2020.01); H02J 2203/20 (2020.01); H02J 2207/50 (2020.01)] 14 Claims
OG exemplary drawing
 
1. A method for sensitive equipment (SE) voltage sag control based on flexible multiplexing of an energy storage system, comprising:
constructing a topological structure for a hybrid energy storage system to control a voltage sag, wherein the hybrid energy storage system includes a lithium battery energy storage system and a supercapacitor, controlling of an early stage of the voltage sag is achieved by the supercapacitor, and continuous controlling of a late stage of the voltage sag is achieved by the lithium battery energy storage system;
achieving real-time and accurate detection of the voltage sag on a grid side and a load side by adopting an improved variational mode decomposition detection approach based on a Teager-Kaiser energy operator and a kurtosis coefficient;
achieving optimal energy compensation through flexible switching in an input stage and an output stage adopting a flexible optimal energy compensation strategy to prevent SE from tripping due to a phase jump caused by the optimal energy compensation;
on a DC/DC side, coordinating power output through power frequency division control according to a difference in response features between the supercapacitor and the lithium battery energy storage system;
on a DC/AC side, performing composite control through a voltage feedforward loop, a voltage feedback outer loop, and a current feedback inner loop, and eliminating a secondary effect of harmonics on the SE using a proportional integral quasi-resonance controller.