Stability Analysis and Simulation of Dynamic Behavior of Virtual Synchronous Generator in Microgrid System Using Small Signal Model

The penetration of renewable power production units in electrical networks through power electronic converters due to their low rotating inertia, leads to increased frequency fluctuations and reduced power system stability. The synchronization of the power converters with the main network is of great importance, so that it must be maintained even during disturbances. Virtual synchronous machines are among the efficient methods to comply with the scarcity of inertia in the power network. In this paper, the aim is to investigate the stability and simulate the dynamic behavior of connecting a virtual synchronous generator (VSG) to an infinite bus employing a small-signal representative. The characteristics of the VSG are compared with the droop method for controlling active and reactive powers. An evaluation between these two different control strategies has been carried out using simulation results in the MATLAB environment. Also, the attributes of the synchronous machines due to changes in the point of damping and inertia parameters are shown. For the accuracy of the simulation results, the small signal model of the studied system has also been implemented in MATLAB/Simulink. Integrating the VSG in the microgrid, in addition to reducing frequency and voltage deviations, also improves stability.