Black Start Scheme of Wind-storage Combined System Based on Virtual Synchronous Generator Control

With a high proportion of wind power generations connected to the grid, wind power generation is expected to be a black-start source. This paper proposed a black start scheme based on virtual synchronous generator (VSG) control for wind-storage combined system. The energy storage inverter was transformed into a VSG with the secondary frequency regulation ability by improved frequency synchronous control (IFSC), and a conventional VSG controller was designed for the rotor side inverter of doubly fed induction generator. And a control mode switching device was designed for the energy storage in order to maintain the grid stability after black start. This paper built the model of wind-storage combined system on the Matlab/Simulink for black start simulation. The simulation results show that the maximum frequency deviation is 68.75% lower than the conventional control when the ancillary machines of wind turbines were restored. What's more, the maximum frequency deviation shall not exceed 0.12%, and the maximum voltage deviation shall not exceed 8% during the black start process and the controllers can realize no-error frequency adjustment. Finally, control mode switching device can smoothly switch IFSC to VSG. Thus, the effectiveness of the proposed black start scheme and controllers are verified.