基于虚拟转速动态调节的构网型逆变器故障穿越控制策略OA

[Objective]The large-scale integration of inverter-based renewable generation introduces new challenges for power-system stability.Although virtual synchronous generator(VSG)control imparts virtual inertia and damping,grid short-circuit faults can induce excessive currents that threaten synchronization and may cause inverter disconnection.This paper proposes a VSG fault ride-through strategy based on dynamic virtual velocity regulation.[Methods]The transient behavior of the VSG under fault conditions is analyzed to identify the source of overcurrent,and dynamic virtual angular velocity regulation is introduced to maintain power-angle stability.The reactive-power control loop is reinforced to improve reactive-power compensation,and a voltage-current dual-loop structure based on the balanced-current method is employed to ensure balanced three-phase output currents.[Results]Matlab/Simulink simulations show that,during grid short-circuit faults,the virtual angular velocity and power angle stay close to their rated values;short-circuit current is limited to within 1.5 times the VSG's rated current;the VSG provides reactive power in accordance with national grid connection codes;output currents remain three-phase balanced;and fault impact currents are effectively suppressed.[Conclusions]Compared with existing methods,the proposed strategy more effectively stabilizes virtual angular velocity and power angle,limits short-circuit and fault impact currents,accelerates transient response,maintains balanced three-phase outputs,and ensures secure,stable VSG operation under grid short-circuit conditions.