###### Abstract  
The given power and grid frequency disturbances can cause transient oscillations and steady-state deviations in the output power of a virtual synchronous generator (VSG), which can be effectively addressed by adding transient damping. However, this approach may result in significant power overshoot. This article proposes an improved VSG control strategy based on transient electromagnetic power feedback compensation and a small-signal model reduction scheme. Firstly, the grid-connected active closed-loop small-signal models of typical VSG control and transient damping VSG control are established, respectively. The transient oscillation suppression mechanism of active power is revealed through root locus and frequency response analyses, and the power overshoot characteristics of the two control strategies are analysed by combining them with the system of zero points. Secondly, the active transient feedback compensation method and the small-signal model reduction design method are introduced in detail. Finally, comparative analysis experiments are conducted using the Matlab/Simulink and hardware-in-the-loop experimental platform. It is verified that the proposed control strategy can suppress transient oscillations in active power, prevent steady-state deviations, and effectively mitigate the power overshoot problem of the system. virtual synchronous generator; power overshoot; transient oscillation; steady-state deviation; root locus analysis; small-signal model +
Footnote †: journal: Physics Letters A  
article  
[color=gray!20,linecolor=gray! frequency regulation characteristics of the VSG, leading to a larger steady-state deviation when the grid frequency deviates from its nominal value [11; 12]. Consequently, a conflict emerges between the transient and steady-state characteristics of TVSG upon grid connection. This suggests that effectively suppressing transient oscillations and concurrently rectifying the steady-state deviation induced by the fixed damping coefficients of the TVSG is a complex issue [13; 14]. Scholars have undertaken extensive research to address the aforementioned conflict and enhance the system's active response performance. This paper primarily investigates adaptive virtual inertia damping [15] and equivalent damping ratio methods [16]. Within the adaptive virtual inertia damping method, reference [17] introduces a Bang-Bang control strategy predicated on the intermittent alternation of virtual inertia. This strategy alternately sets the maximum and minimum values of virtual inertia based on the angular frequency deviation and its rate of change. However, the intermittent selection of virtual inertia can undermine the system's stability. Reference [18] proposes a Bang-Bang control strategy grounded in continuous adaptive virtual inertia, which mitigates the transient oscillation issue induced by the intermittent setting of virtual inertia. References [19; 20; 21] investigate continuous adaptive control strategies based on the coordination of virtual inertia and damping coefficients from diverse control perspectives, thereby further enhancing the dynamic response characteristics of the TVSG during grid operation. However, these methods depend on fixed damping control strategies, with virtual inertia and damping coefficients remaining unchanged during steady-state conditions. This limitation fails to resolve the steady-state deviation in grid-connected active power due to the interaction between damping and PFR characteristics. Moreover, inadequate parameter adaptation can further undermine the stability of the TVSG during grid-connected operation [22]. The equivalent damping ratio method decouples the system's dynamic and static characteristics by introducing transient damping. This approach effectively suppresses transient oscillations while addressing steady-state deviations caused by damping characteristics [23].