Low-Voltage Ride-Through Method for Grid-Forming Converter Based on Adaptive Virtual Impedance

Due to the good weak grid adaptability and grid support capability, Grid-Forming (GFM) energy storage converter is considered to be an effective solution for the grid-connected interface of new power systems. When a symmetrical low-voltage fault occurring, grid-forming converters may face transient overcurrent problems during the fault and recovery phases. A virtual synchronous generator (VSG)-controlled GFM converter is take as the research object in this paper and a low-voltage ride-through (LVRT) control method of GFM converter is proposed, which realizes the current limitation of GFM converter under low-voltage fault by using adaptive virtual impedance. On the basis of guaranteeing the voltage source characteristics of GFM converter, L VRT control method injects reactive current into the grid according to standards. Finally, based on the Simulink/Matlab simulation platform, the effectiveness of L VRT control method for transient current suppression is verified.