基于自适应虚拟阻感比的构网型变流器故障穿越控制方法OA

Virtual impedance control is commonly employed by grid-forming renewable energy sources during fault ride-through to achieve fault current limitation while maintaining voltage source characteristics to support the grid.However,existing virtual impedance methods that use a fixed resistance-to-inductance(X/R)ratio lack the flexibility to control reactive power output and to provide adequate voltage support.To address this issue,this paper proposes a fault ride-through control method for the grid-forming(GFM)converter based on an adaptive virtual X/R ratio.First,the influence of the virtual X/R ratio on active and reactive power characteristics is analyzed.Then,considering three control objectives—transient voltage support,peak current limitation,and system synchronization stability—a constraint boundary for the virtual X/R ratio of the GFM converter is established in the virtual impedance plane.Based on this boundary,a dynamic selection method for the X/R ratio is developed to achieve the synergistic optimization of the three objectives.Simulation results demonstrate that the proposed method significantly enhances the GFM converter's voltage support capability during fault ride-through.Compared with existing methods,it increases reactive power output during the fault by over 30％without violating the converter's operational safety limits,as verified in PSCAD/EMTDC.