Cooperative control of battery energy storage systems in microgrids

• Published in: International journal of electrical power & energy systems 2017-05, Vol.87, p.109-120
• Main Authors: Hosseinimehr, Tahoura, Ghosh, Arindam, Shahnia, Farhad
• Format: Article
• Language: English
• Subjects: Distributed Energy Resource (DER); Dynamic power sharing; Microgrid; Virtual impedance
• ISSN: 0142-0615; 1879-3517
• DOI: 10.1016/j.ijepes.2016.12.003

•A cooperative control of battery energy storage (BES) systems is proposed.•The proposed control strategy comprises two control subsystems, for charge and discharge operation of the BES.•Employing the proposed method in both charge and discharge mode aims to maintain the power balance of the microgrid (MG), while respecting the SoC level and power rating of the BESs.•Moreover, a new virtual impedance strategy is introduced in order to enhance the reactive power sharing accuracy among the BES units and the renewable energy sources (RESs) in the MG.•The system performance is validated through extensive simulations carried out in PSCAD/EMTDC software. This paper proposes a cooperative control of battery energy storage (BES) units within a microgrid (MG) which includes two control subsystems for charge and discharge operation mode of the BES. In addition, the proposed cooperative control strategy provides accurate reactive power sharing among the BES units. During discharge operation, the proposed strategy utilizes a SoC-based droop control in order to avoid promptly depleting of the BES units, by dedicating the highest priority to their SoC level and respecting their power rating. This is achieved without any disturbance in the power balance of the MG. In addition, during charge operation of the BES units, the proposed control method uses a proportional-integral (PI) controller to limit the BES absorbing power and match it with the available surplus power from the renewable energy sources (RESs). This in turn avoids any power imbalance within the system. Finally, to utilize the extra capacity of the BES converters and also to avoid overloading of RESs, a new adaptive virtual impedance (AVI) strategy is proposed here which provides accurate reactive power sharing by imposing a virtual impedance in series with the coupling impedance of each BES and RES unit. The system performance is validated through extensive simulations carried out in PSCAD/EMTDC software.