Optimal Reactive Power Control Strategy for Islanded VSG System under Sliding Mode Control

In microgrid systems, virtual synchronous generator (VSG) serves as an interface to various distributed power sources, which can effectively improve the inertia and damping of the system. The VSG system under conventional linear control has low control accuracy and poor perturbation resistance, to which this paper introduces adaptive perturbation compensation on the basis of conventional sliding mode control, which improves the robustness of the system on the basis of ensuring the stability of the system. Meanwhile, for the problem that reactive power cannot be proportionally distributed and circulating current is generated due to the inconsistency of line impedance when multiple VSGs are connected in parallel, a consensus-based adaptive virtual impedance control strategy is proposed, which realizes the precise distribution of reactive power and effectively suppresses the circulating current at the same time. Finally, the reliability and superiority of the above control strategy are verified by simulation.