Grid-Forming Control Explored from Mathematical Science of Frequency Synchronization

In this article, from the viewpoint of mathematical science, we clarify a class of mathematical models with grid-forming function by considering the principle of frequency synchronization. In particular, it is shown that the two-axis model and classical model of the synchronous generator, and the frequency-droop-control model are all equivalent in terms of frequency synchronization. It is also explained that systematic stability analysis with a generalized synchronizing power coefficient matrix, derived as the Hessian of a strain energy function, is possible for all those models. © 2022 The Institute of Electrical Engineers of Japan.