海上风电机组主动频率支撑及故障穿越策略OA

To address the problems of voltage sag,power-angle oscillation,and excessive fault current in hybrid grid-connected systems with grid-following and grid-forming converters under high-penetration offshore wind power during severe short-circuit faults,an active frequency support and fault current suppression strategy for offshore wind turbines is proposed.First,a fault current model of the hybrid grid-connected system under a three-phase short-circuit fault is established,and the formation mechanisms of its dc and ac components are analyzed.Then,for the grid-forming converter,improved VSG control and virtual impedance control are adopted to suppress the fault current.For the grid-following converter,a seamless switching strategy between current-limiting mode and grid-forming mode is designed,and a feasible-domain model of control parameters is constructed.Finally,the proposed control method and the parameter feasible-domain analysis results are verified in MATLAB/Simulink.The results show that,compared with conventional control,the proposed strategy can reduce the steady-state fault current by approximately 20%and increase the voltage at the point of common coupling by approximately 10%,providing a reference for fault ride-through control and parameter tuning.