Improved transient stability analysis method of power system with VSG inverter based on SMR

In order to reduce the effect of total inertia reduction on system stability after high penetration distributed power access, virtual synchronous generator technology(VSG) has become a research hotspot. In transient process, the inverter with VSG technology has similar dynamic behavior as synchronous machine. And traditional direct method has a certain conservatism in the analysis of transient stability. In this paper, an improved direct method based on SMR technology is proposed to analyze the transient stability of the power system with VSG inverter. By analyzing the virtual power angle transient characteristics of inverter with VSG strategy, a virtual power angle dynamic model is constructed, and the traditional direct method is improved by using SMR technology. Finally, the method is simulated by using the SMIB and IEEE three-machine nine-node systems. The results show that the improved direct method can correctly acquire the transient stability index and reduce the conservation of traditional method.