Contents I. Introduction
In recent times, the energy crisis has escalated, leading to the rapid advancement of new energy grid-connected power generation, primarily reliant on photovoltaic and wind power. Nevertheless, the power electronic apparatus extensively employed in the new energy power generation system fails to furnish the requisite inertia bolster for the power network. As the proportion of new energy progressively improves, the stability of power grid operation will face formidable challenges [1], [2]. The energy storage virtual synchronous generator (VSG) introduces virtual inertia and damping response links by simulating the power swing equation of the traditional synchronous generator, thereby possessing external characteristics comparable to the conventional synchronous generator and providing some inertia support for the power grid [3]. However, virtual inertia results in upgrading the active power-frequency control loop of the energy storage VSG to a second-order system, causing dynamic oscillations and overshoot in its grid-connected active power under disturbances such as the power command and grid frequency [4]. Additionally, the energy storage VSG has the capability to utilize the virtual damping control link to suppress or eliminate the dynamic oscillations of its grid-connected active power under two types of disturbances by increasing the virtual damping parameter. However, the coupling between the virtual damping parameter and the primary frequency modulation parameter restricts the ability to independently adjust the damping response performance and primary frequency modulation characteristics. Specifically, designing the primary frequency modulation coefficient based on active power- frequency control may result in significant dynamic oscillations of VSG output active power. Conversely, designing the damping coefficient according to damping feedback characteristics will equivalently alter the primary frequency modulation coefficient, potentially leading to a substantial steady-state deviation of VSG output active power when there is a deviation between the grid frequency and the rated frequency [5]. Therefore, enhancing the damping feedback control strategy of VSG is imperative to resolve the coupling problem between its active power-frequency characteristics and damping characteristics, which conflict with its dynamic and steady-state performance.
