Cooperative Control Strategy of Multiple VSGs in Microgrid Based on Adjacent Information

Abstract

As an interface between distributed power source and large power grid, microgrid has attracted more and more attention. Due to the lack of inertial support for the power system, the virtual synchronous generator (VSG) technology that can simulate the external characteristics of synchronous generators came into being. Aiming at the problem of power and frequency oscillation in microgrid after the introduction of VSG technology, this paper conducts small-signal modeling of multiple VSGs in parallel, analyzes their operating characteristics, and proposes a multiple VSGs cooperative control strategy based on adjacent information. Depend on the adjacent information, the strategy optimizes the output control of each VSG, which makes each VSG tend to the same output frequency at any time. Therefore, the proposed strategy can suppress the power and frequency oscillation, and improve the dynamic characteristics of the system. In this paper, the stability of the proposed control strategy is studied by Lyapunov stability theory, and the effectiveness of the proposed control strategy is verified by simulation.

Keywords

• Microgrid
• virtual synchronous generator
• cooperative control
• Lyapunov stability