Open Access
ARTICLE
Automatic SOC Equalization Strategy of Energy Storage Units with DC Microgrid Bus Voltage Support
Jingjing Tian1, Shenglin Mo1,*, Feng Zhao1, Xiaoqiang Chen2
1 School of Automation & Electrical Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China
2 Key Laboratory of Opto-Technology and Intelligent Control (Lanzhou Jiaotong University), Ministry of Education, Lanzhou, 730070, China
* Corresponding Author: Shenglin Mo. Email:
Energy Engineering 2024, 121(2), 439-459. https://doi.org/10.32604/ee.2023.029956
Received 15 March 2023; Accepted 23 August 2023; Issue published 25 January 2024
Abstract
In this paper, an improved sag control strategy based on automatic SOC equalization is proposed to solve the problems of slow SOC equalization and excessive bus voltage fluctuation amplitude and offset caused by load and PV power variations in a stand-alone DC microgrid. The strategy includes primary and secondary control. Among them, the primary control suppresses the DC microgrid voltage fluctuation through the Ⅰ and Ⅱ section control, and the secondary control aims to correct the
P-U curve of the energy storage system and the PV system, thus reducing the steady-state bus voltage excursion. The simulation results demonstrate that the proposed control strategy effectively achieves SOC balancing and enhances the immunity of bus voltage. The proposed strategy improves the voltage fluctuation suppression ability by approximately 39.4% and 43.1% under the PV power and load power fluctuation conditions, respectively. Furthermore, the steady-state deviation of the bus voltage, ΔU
dc is only 0.01–0.1 V, ensuring stable operation of the DC microgrid in fluctuating power environments.
Keywords
Cite This Article
APA Style
Tian, J., Mo, S., Zhao, F., Chen, X. (2024). Automatic SOC equalization strategy of energy storage units with DC microgrid bus voltage support. Energy Engineering, 121(2), 439-459. https://doi.org/10.32604/ee.2023.029956
Vancouver Style
Tian J, Mo S, Zhao F, Chen X. Automatic SOC equalization strategy of energy storage units with DC microgrid bus voltage support. Energ Eng. 2024;121(2):439-459 https://doi.org/10.32604/ee.2023.029956
IEEE Style
J. Tian, S. Mo, F. Zhao, and X. Chen "Automatic SOC Equalization Strategy of Energy Storage Units with DC Microgrid Bus Voltage Support," Energ. Eng., vol. 121, no. 2, pp. 439-459. 2024. https://doi.org/10.32604/ee.2023.029956