Robust Control Algorithm for Virtual Synchronous Generator in Intermittent Generation

Abstract

This work presents a comparison of two control algorithms for the model of a nonlinear converter system used as a virtual synchronous generator (VSG). The converter connects between the electrical grid and an intermittent renewable system, such as photovoltaic or wind, with backup for sudden disturbances in electricity generation. The proposal of the VSG arises from the fact that, on one hand, the conventional generation system consists of large power plants such as combined-cycle power plants that employ generators and turbines with significant physical inertia. On the other hand, when connecting renewable systems such as wind and solar, which use converters to integrate with the grid, they lack physical inertia. It is necessary to couple this inertia to the system in order to compensate for the disturbances of intermittent systems and thereby maintain the frequency of the electrical power network. It should be clarified that physical inertia is not available when renewable systems such as wind or photovoltaic are connected. Recent studies have shown that it is possible to compensate for the disturbance caused by this lack of inertia through a backup system and the virtual synchronous generator (power converter) using control algorithms. In this work, linearization and super twisting algorithms are employed for handling disturbances, and the main differences between the algorithms are demonstrated when facing sudden changes in active or reactive power.