Distributed cooperative control for global power sharing management of interconnected microgrids in flexible multi-terminal DC connection scheme

• Published in: Electric power systems research 2024-12, Vol.237, p.110969, Article 110969
• Main Authors: Meng, Xiaoxiao, Wang, Yuchen, Shao, Bingbing, Mao, Xun, Wang, Qianggang
• Format: Article
• Language: English
• Subjects: Bidirectional interlinking converters; Distributed cooperative control strategy; Interconnected microgrids; MTDC connection scheme; Power sharing management
• ISSN: 0378-7796
• DOI: 10.1016/j.epsr.2024.110969

•The inherent difference between global active and reactive power sharing schemes is discussed and revealed. Two suitable communication topologies and their constraint requirements for global active/reactive power sharing management are discussed and proposed based on graph theory.•Precise global power sharing management are fulfilled. BICs can cooperatively adjust their power outputs with the frequency and active/reactive power sharing rate signals based on communication with neighbors. Accurate global active/reactive power sharing management is achieved, and the frequency and bounded voltage are restored.•The consensus and stability of the proposed cooperative control strategy are proved. The Lyapunov function of the dominated modes in the proposed two-layer method is built. The consensus and stability are thoroughly investigated and proved. Flexible multi-terminal direct current (MTDC) connection scheme is an ideal way to integrate multiple adjacent microgrids and form interconnected microgrids (IMGs). However, under the traditional control mode, MTDC will lead to frequency/voltage decoupling among all the microgrids. Moreover, improper control scheme design of bidirectional interlinking converters (BICs) in MTDC will make global active/reactive power sharing management impossible, which is considered as the significant task in IMGs. Therefore, a novel distributed cooperative control strategy is designed in this article. In the proposed control strategy, frequency/voltage regulations and local active/reactive power sharing management are achieved through distributed secondary control within each MG. Accurate global active/reactive power sharing management is realized by coordinating the power exchange instructions of each BIC in a distributed manner. The control dynamics of these two levels are designed to be decoupled. The stability of the proposed control strategy is demonstrated by the Lyapunov method, and its effectiveness is verified by simulating a test IMG system in MATLAB/Simulink.