A comprehensive review of virtual synchronous generator

The renewable energy resources based distributed generation (DG) unit's integration into the power system is growing rapidly, and the power system experiencing low inertia and damping, which causes severe stability and performance issues of the power system. In order to facilitate the integration of DG into the existing power system, improved control schemes for grid-tied electronic converters are necessary to ensure the stability and support to the power system. The virtual-synchronous generator (VSG) control emulates the dynamics of the rotation synchronous generator and enhances the stability of the power system. In this paper, an overview of different topologies to virtual inertia is presented along with a detailed description of the VSG structure. Moreover, VSG control defining active and reactive power control, and voltage and frequency control is explained in detail. The VSG stability analysis methods, such as small signal stability and transient stability are presented in comprehensive manners. Later on, the VSG application fields are described. Finally, the VSG problems and future research directions such as centralised control, stability improvement, reliable modelling, the interface for VSG are discussed.