Optimization Control for Frequency Regulation Response Speed in Grid-Forming Energy Storage Converters Based on Adaptive Mode-Switching

With the increasing penetration of renewable energy sources (RESs) in the power grid, the active support capability of power conversion systems (PCSs), which serve as the critical link between RESs and the grid, has become increasingly vital. In this paper, an optimized control strategy for frequency regulation of response speed in grid-forming energy storage converters based on adaptive mode-switching is proposed. When power fluctuations are detected, the system switches to droop control, and reverts to virtual synchronous generator (VSG) control when frequency stability is nearly restored. Experimental results demonstrate that during load transients, the proposed control strategy significantly improves the frequency regulation response speed of the energy storage converter compared to conventional VSG and droop control, achieving a reduction in regulation time within the range of 40% to 70%, while also reducing overshoot, as validated by both simulation and hardware-in-the-loop experiments.