Comparison of Low Frequency Oscillation Characteristic Differences between VSG and SG

Abstract

Virtual synchronous generator (VSG) was a control strategy for inverter generators (IGs) to overcome the shortcomings of small inertia and low damping by simulating the rotor operating mechanism of synchronous generators (SGs). The stability of VSG is very important for its application. At present, the related research mostly focuses on the VSG itself and its application in microgrid. There is few research to explain how VSG effecting the low frequency oscillation in transmission power system. This paper built a small-signal model of VSG-SG interconnected system, which is suitable for the study of low frequency oscillation damping characteristics of the transmission power grid. Based on the model, the effect of VSG on the low frequency oscillation were compared with the effect of SG to reveal the mechanism of how VSG affecting the damping characteristic.