Frequency Modulation Control of Grid-Forming Converter Based on LADRC-MI

The increasing proportion of new energy in the power system leads to a decrease in system inertia and weakens the frequency stability of the system. The use of grid-forming (GFM) control for inverters is an effective method to improve frequency stability in new energy generation systems. Due to uncertain disturbances in microgrids, it can cause changes in system frequency. A control strategy for linear active disturbance rejection control combined with model information (LADRC-MI) is proposed in this manuscript. In this method, the inertia level and damping of the system are improved by using virtual synchronous generator (VSG)-based GFM control. Then, the obtained part of the model information is written into the coefficient matrix of the linear extended state observer. The LADRC-MI is constructed to improve the immunity of the controller. Finally, the effectiveness of the strategy in improving the immunity and frequency stability of the converter is analyzed and verified.