The control strategy for distributed energy storage devices using fully diffusion strategy

作     者：Liu, Zejian Yang, Ping Lin, Xu Fan, Ziwei Hong, Cencen 

作者机构：Key Laboratory of Clean Energy Technology of Guangdong Province School of Electric Power Engineering South China University of Technology Guangzhou 510640 China Power Dispatch Control Center Guangdong Power Grid Corporation Guangzhou 510699 China Shenzhen Huagong Energy Technology Co. Ltd Shenzhen 518100 China School of Automation Nanjing Institute of Technology Nanjing 211167 China 

出 版 物：《Heliyon》 (Heliyon)

年 卷 期：2025年第11卷第3期

页      面：e42175页

基　　金：Marine Economic Development Six Marine Industries) Special Fund Project of Guangdong Province, (GDNRC27) 

主　　题：Diffusion strategy Energy storage device unit (ESU) State-of-charge (SOC) equalization Voltage compensation 

摘      要：The distributed energy storage device units (ESUs) in a DC energy storage power station (ESS) suffer the problems of overcharged and undercharged with uncertain initial state of charge (SOC), which may reduce the service period of ESUs. To address this problem, a distributed secondary control based on diffusion strategy is proposed. In the first layer, each ESUs operates with its local controller by droop control. In the second layer controller, diffusion strategy coordinate the SOC of multiple distributed ESUs with uncertain initial SOC. Compared with centralized control, the proposed method contributes to a higher scalability and reliability. Diffusion strategy allows adjacent nodes to diffuse and cooperate information in real-time, and it includes a stochastic gradient term. Thus, diffusion strategy can achieve a higher convergence rate and lower mean-square-error than consensus strategies. For the second layer controller, first the coordinated control of ESUs is transformed into two optimization problems: the balanced output voltage and the balanced SOC of each ESU. Then, diffusion strategy is used to solve the optimization problems. Finally, a simulation model is built to verify the effectiveness of diffusion strategy. The results show that diffusion strategy always ensure the stability irrespective of the combination topology. Compared with the widely used consensus method, diffusion strategy shows a good performance in realizing demand response for distributed ESUs. © 2025