The virtual synchronous generator (VSG) provides a promising solution to integrate a high penetration of inverter-based sources into the power system without threatening the frequency and voltage stability, which may solve the problem that the traditional maximum power point tracking (MPPT) control cannot provide the necessary ancillary. Due to different design principles, the impact of the VSG on the power system may be quite different compared with the traditional synchronous generators (SGs). This paper aims to study the impact of replacing SGs with VSGs on the electromechanical oscillation of the power system. It starts with the comparison of modeling between VSGs and SGs and establishment of a general small-signal model representing both the SGs and VSGs with frequency and voltage regulation. Accordingly, a comprehensive small-signal analysis is executed in details in order to study the changing of electromechanical dynamics. Finally, simulation results in Matlab/Simulink verify the analysis. It shows how the states of a VSG will influence the electromechanical oscillation by changing the participation factors in those modes.

虚拟同步发电机（VSG）提供了一种很有前景的解决方案，可以在不威胁频率和电压稳定性的情况下将基于逆变器的高渗透源集成到电力系统中，这可能会解决传统最大功率点跟踪（MPPT）控制无法解决的问题。提供必要的辅助。由于设计原理不同，VSG对电力系统的影响可能与传统的同步发电机（SG）有很大不同。本文旨在研究用VSGs代替SGs对电力系统机电振荡的影响。它首先比较 VSG 和 SG 之间的建模，并建立代表 SG 和 VSG 的具有频率和电压调节功能的通用小信号模型。因此，为了研究机电动力学的变化，详细执行了全面的小信号分析。最后，在 Matlab/Simulink 中的仿真结果验证了分析。它显示了 VSG 的状态如何通过改变这些模式中的参与因子来影响机电振荡。