## 8 Conclusions  
To tackle the challenges of transient oscillations, steady-state deviations, and power overshoot inherent in traditional VSG control strategies under given power and grid frequency disturbances, this paper proposes a VSG control strategy utilizing active power transient feedback compensation. This strategy integrates small-signal modeling with root locus distribution trends to provide a comprehensive theoretical analysis. The conclusions drawn from both simulations and HIL experiments are as follows:  
Figure 18: Experimental results: (**a**) comparative experimental results of different control strategies under given power disturbance; (**b**) Comparative experimental results of different control strategies under grid frequency drop. 1. The TVSG based on fixed damping control cannot simultaneously satisfy the system's needs for transient oscillation suppression and steady-state deviation correction. Based on the transient characteristics simulation analysis of TVSG control, it is observed that as the fixed damping coefficient increases, the transient oscillation suppression performance of the TVSG improves, but the dynamic response rate slows down. Additionally, grid frequency disturbances result in a significant steady-state deviation. 2. Based on the transient characteristic simulation analysis of TDP-VSG control, it can be observed that introducing transient damping eliminates the steady-state deviation caused by damping characteristics. However, the system's zero point in TDP-VSG control is positioned near to the imaginary axis, resulting in a significant power overshoot. Additionally, the transient damping coefficient is positively correlated with power overshoot during grid frequency disturbances. Thus, while TDP-VSG control effectively suppresses transient oscillations, it also encounters a substantial power overshooting problem. 3. According to the transient oscillation suppression mechanism of the APFBC-VSG control based on root locus analysis, the proposed control strategy can effectively suppress transient oscillations without increasing the steady-state deviation. The zero point distribution trend shows that the zero point introduced by the APFBC-VSG control is farther from the imaginary axis, avoiding power overshooting under given power and grid frequency disturbance. 4. Establishing the active closed-loop small-signal model for the proposed APFBC-VSG control, combined with root locus analysis of varying control parameters, reveals that the delay time constant has a negligible impact on oscillation suppression. In contrast, the transient compensation coefficient is crucial in enhancing oscillation suppression performance. A small-signal model step-down simplification method is proposed, and its effectiveness is validated through frequency response analysis comparing the model before and after reduction. This provides a solid theoretical foundation for subsequent parameter design methods. This paper exclusively examines the transient oscillation suppression capabilities of APFBC-VSG control under given power and grid frequency disturbances. The subsequent research will focus on the proposed control strategy's ability to enhance system stability in parallel grid connections and optimize performance when integrated with energy storage systems. Conceptualization, Y.X. and Y.C. ; methodology, Y.X. ; validation, Y.X., Y.C. and H.L. ; formal analysis, Y.X. and H.L. ; investigation, Y.X. and Y.C. ; resources, R.C. and K.L. ; writing--original draft preparation, Y.C. ; writing--review and editing, Y.X., J.S. and Y.Y. ; supervision, J.S. and Y.Y. ; project administration, Y.X., R.C. and K.L. All authors have read and agreed to the published version of the manuscript.