An IPAVSG Control Strategy for Microgrid With Multi-Parallel VSG System

Abstract

Virtual synchronous generator (VSG) is widely used in various distributed power generation systems due to great simulated inertia and damping support performance. However, when the microgrid (MG) composed of multi-parallel VSG is in both grid-connected and islanded modes with various large disturbances, the control strategy with fixed parameters cannot guarantee the stable operation of the MG under all disturbances. To this end, an improved parameter-adaptive virtual synchronous generator (IPAVSG) control strategy is proposed in this paper to ensure that the virtual inertia and damping are adaptively optimized with the system operating state during the disturbance process. Therefore, the dynamic performance of the power frequency regulation and transient stability are significantly improved. Meanwhile, in order to realize the output active power of each VSG is distributed among the loads according to the ratio of its rated capacity, the active power decoupling control is designed to eliminate the influence of the virtual damping on the output active power of the VSG in islanded MG. The effectiveness and practicability of the proposed control strategy are verified through several experiments.