Frequency Control Method of GFM Converter Combined with Improved LADRC Controller

With the increasing proportion of new energy generation in the power system, the inertia of the system becomes smaller than before and the frequency stability is weakened. Due to the deepening development of control technology, grid-forming (GFM) is increasingly being used. In order to solve the problem of frequency change caused by uncertain disturbance in microgrid, an improved linear active disturbance rejection control strategy is proposed. In this method, GFM control based on virtual synchronous generator (VSG) is used to improve the inertia level of the system, and then part of the obtained model information is combined with the linear extended state observer to improve the observation speed of the observer. Finally, a simulation model is established in Matlab/Simulink, and the effectiveness of the improved strategy in improving the immunity and frequency stability of the inverter is analyzed and verified.