Distributed Hybrid Secondary Control for a DC Microgrid via Discrete-Time Interaction

• Published in: IEEE transactions on energy conversion Vol. 33; no. 4; pp. 1865 - 1875
• Main Authors: Liu, Xiao-Kang, He, Haibo, Wang, Yan-Wu, Xu, Qianwen, Guo, Fanghong
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.12.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Communications systems; Control stability; Control systems design; Current sharing; Data buses; DC microgrid; Design parameters; Direct current; discrete-time communication; Distributed generation; Dynamic control; Dynamic stability; Electric potential; Electronic mail; hybrid system; Hybrid systems; Impedance; impulsive control; Microgrids; Resistance; Stability analysis; Topology; Voltage control
• DOI: 10.1109/TEC.2018.2850279
• ISSN: 0885-8969

This paper studies the current sharing problem of a dc microgrid using the hybrid dynamic control method. The hybrid dynamic controller framework is established including a continuous-time part and a discrete-time part, where the former part eliminates the voltage deviation of the dc bus and the latter part ensures the current sharing accuracy of the dc microgrid. The proposed distributed hybrid secondary controller not only guarantees a high accuracy of current sharing but also maintains the voltage regulation at the dc bus. Different from most existing methods, it only utilizes the sampling output current information of neighbors at the discrete time instants, which greatly reduces the communication burden. Under the framework of stability analysis on the closed-loop system, the proposed hybrid dynamic controller achieves both current sharing and voltage regulation if the average interacted interval of the discrete time interaction satisfies a bounded constraint. Besides, a detailed parameter design of the controller is provided. Finally, simulation and experimental tests are presented to demonstrate the effectiveness of the proposed method.