Wind power, photovoltaic, and other new clean energy generations exhibit large power fluctuations and strong intermittency, whose rapid integration leads to grid frequency instability and even major blackouts. Energy storage systems are thus urgently required to improve the grid’s flexible regulation capability. The variable speed pumped storage unit with full‐size converter (FSC‐VSPSU) can provide large‐capacity, fast, and flexible regulation resources, making it increasingly widely applied. However, during its rapid regulation, the significant time‐scale difference between the converter controller and turbine governor causes a reverse regulation phenomenon, which seriously endangers unit safety. To address this problem, this study first clarifies the specific mechanism of reverse regulation using energy flow diagrams. A novel suppression method based on DC‐side energy storage is then proposed, which is innovative in targeted solving the time‐scale mismatch‐induced reverse regulation issue of FSC‐VSPSU. Finally, a simulation model is established in MATLAB/SIMULINK to verify the reverse regulation mechanism and the effectiveness of the proposed strategy. The simulation results demonstrate that the proposed method can effectively suppress the reverse regulation phenomenon, significantly improving the operational safety and stability of FSC‐VSPSU. This study provides a new technical approach for the stable operation of FSC‐VSPSU in grid flexible regulation.
Pan et al. (Thu,) studied this question.