A simple estimation method of grid‐forming inverter inertia based on rate of change of frequency

Abstract

Abstract Inertia is the core index of the estimation of power system frequency stability; a simple estimation method of grid‐forming inverter inertia based on the rate of change of frequency (RoCoF) is proposed in this paper. The method records and fits the active power curve by applying RoCoF to obtain the value of the grid‐forming inverter inertia, and it is simpler and higher accuracy compared to existing methods. In addition, the inertia and damping are analysed to support the system, and the relationship equation between the grid frequency slope change and the output active power is derived. Considering the theoretical analyses and influencing factors, the inertia and damping are obtained by using the method of function fitting. The test steps show the simplicity of the proposed test method. Finally, the effectiveness of the proposed method is verified in MATLAB/Simulation and two 1.575‐MW parallel grid‐forming electrochemical energy storage power plants.

Keywords

• damping
• frequency estimation
• frequency measurement
• invertors