An improved parameter boundary calculation method for virtual synchronous generator with capacity constraints of energy storage system

•A novel approach to analyze the inertia and damping parameters of virtual synchronous generators (VSG) through bifurcation analysis, aiming to establish the parameter ranges that ensure system stability.•Further investigates the parameter boundary constraints of energy storage system (ESS) on damping parameter, in contrast to previous boundary analysis that primarily utilized ESS capacity constraints on inertia parameter.•Providing a more comprehensive characterization of the inertia and damping parameter boundaries of VSG systems with ESS.•Providing an analytical foundation for the parameter design of the VSG systems with ESS. By introducing inertia and damping parameters, Virtual Synchronous Generator (VSG) control simulates the external characteristics of a synchronous generator and is recognized as a crucial control method for enhancing the stability of renewable energy grid-connected systems. Energy storage system (ESS) is the physical basis for implementing VSG to provide inertia and damping for the system, and in practical engineering applications, the ESS capacity configured by VSG is typically fixed. Based on this, this article proposes an improved ESS constraints calculation method, which not only realizes the traditional ESS constraint on inertia but also further provides the damping constraint. Additionally, considering that the parameter values required to satisfy the ESS constraints may not fall within the stability range of the system, this article conducts a bifurcation analysis of the inertia and damping in VSG systems, deriving the upper and lower limits of inertia and damping necessary for system stability as supplementary constraints for ESS. Furthermore, the constraints of the dynamic response performance of the system on the range of inertia and damping values were also considered. By taking the intersection of the above three constraints, the inertia and damping parameter boundaries can be obtained to prevent the ESS capacity from exceeding the limit while maintaining the excellent dynamic characteristics and stability of the VSG system. Finally, relevant simulation models were built using Matlab/Simulink to verify the correctness and effectiveness of the proposed method.