Improvement of frequency regulation in VSG-based AC microgrid via adaptive virtual inertia

A virtual synchronous generator (VSG) control based on adaptive virtual inertia is proposed to improve dynamic frequency regulation of microgrid. When the system frequency deviates from the nominal steady-state value, the adaptive inertia control can exhibit a large inertia to slow the dynamic process and, thus, improve frequency nadir. And when the system frequency starts to return, a small inertia is shaped to accelerate system dynamics with a quick transient process. As a result, this flexible inertia property combines the merits of large inertia and small inertia, which contributes to the improvement of dynamic frequency response. The stability of the proposed algorithm is proved by Lyapunov stability theory, and the guidelines on the key control parameters are provided. Finally, both hardware-in-the-loop and experimental results demonstrate the effectiveness of the proposed control algorithm.This work was supported in part by the National Natural Science Foundation of China under Grant 61622311, in part by the Joint Research Fund of Chinese Ministry of Education under Grant 6141A02033514, in part by the Project of Innovation-Driven Plan in Central South University under Grant 2019CX003, in part by the Major Project of Changzhutan Self Dependent Innovation Demonstration Area under Grant 2018XK2002, in part by the Scholarship from the China Scholarship Council under Grant 201806370158, and in part by the Hunan Provincial Innovation Foundation for Postgraduate under Grant CX2018B060