BESS-Based Grid-Forming Voltage Support Control with Grid Impedance Estimation in Weak Grids

Grid-forming converters enhance the inertia of weak grids, with the integration of autonomous voltage support becoming a prevailing trend. However, existing autonomous voltage support methods for grid-forming converters exhibit strong dependence on grid impedance and insufficient regulation accuracy, making them unsuitable for dynamic and complex grid environments. To address this issue, this paper proposes a battery energy storage systems (BESS) grid-forming autonomous voltage support method with real-time grid impedance estimation in weak grids. By measuring grid impedance in real time and dynamically estimating its variation trends, the proposed method integrates an autonomous reference power adjustment algorithm to achieve precise control of the output power of the grid-forming converter, thereby optimizing voltage support performance. Simulations in MATLAB/Simulink demonstrate the effectiveness of the proposed strategy.