Dynamic Response of Grid-following and Grid-forming Inverters when encountering disturbances

The integration of renewable energy sources leads to the increase of inverter-based generators, causing a decrease in grid strength and stability issues. To deal with this problem, researchers proposed different control structures of the grid-forming (GFM) control strategy, which can automatically provide active and reactive energy support when the power network encounters disturbances during operation. This paper focuses on the capability of different types of inverters to recover from disturbances when encountering balanced load disturbance and different depths of voltage fault. The theoretical assessment and PSCAD simulations of different control strategies have been conducted. The results indicate that when encountering a fault under weak grid conditions, large frequency and voltage variations will occur in the power network connected with the grid-following (GFL) inverter, while these variations are much smaller in the power network connected with the grid-forming inverter, which demonstrates better dynamic response to disturbance.