Inertia damping identification method for grid type inverters based on RCOF

The current inertia testing method for inverters is complex and difficult to apply to grid-forming converter. This article proposes an inertia damping identification method for grid-forming converter based on the rate of change of frequency (RoCoF), analyzes the working mechanism of active power control for grid-forming converter, derives the relationship between active power of grid-forming converter and grid frequency slope disturbance, and provides the inertia and damping identification steps based on this relationship. Finally, the proposed method is validated in a 3.15MW grid type electrochemical energy storage unit and optimized using Kalman filtering, and the experimental results show that the maximum measurement error of the proposed method was only 1.6%, indicating its effectiveness and feasibility.