Research on Parameter Adaptive Control Strategy of Virtual Synchronous Generator

The virtual synchronous generator control introduces the synchronous generator rotor motion equation into the control of the grid-connected inverter to realize the friendly grid connection of the distributed power source. However, a part of the dynamic adjustment performance of the grid-connected inverter is lost. Improper selection of the moment of inertia and damping coefficient of the virtual synchronous generator may cause the "rocking" oscillation phenomenon, which is similar to the synchronous generator, appearing in the grid-connected inverter, and even cause the grid-connected inverter to be off-grid. Therefore, the virtual synchronous generator parameter adaptive control is proposed for the moment of inertia and damping coefficient. Firstly, the mathematical model of the virtual synchronous generator is established, and the influences of moment of inertia and damping coefficient on the performances of virtual synchronous generator is analyzed. Furthermore, the adaptive control of moment of inertia and damping coefficient is introduced into the virtual synchronous generator control. Finally, the effectiveness of the proposed control strategy is verified by MATLAB/Simulink simulation. The results show that the parameter adaptive virtual synchronous generator control improves the system response speed and reduces effectively the virtual synchronous generator frequency and power overshoot, compared with the fixed-parameter virtual synchronous generator control.