With the continuous expansion of wind power integration

dual-sequence synchronization stability has become a critical concern for wind farms under asymmetrical grid faults. In particular

in multi-parallel systems

stability analysis is further complicated by various coupling effects. To address this challenge

a dual-sequence nonlinear dynamic model is developed to identify and characterize three types of coupling interactions. By incorporating the equal area criterion

the impact of coupling effects on dual-sequence synchronization stability under different scenarios is analyzed. On this basis

a method for calculating the coupling critical point is developed under accordance with grid code requirements

which can be utilized to determine appropriate current injection levels for wind farms. Finally

simulation results are presented to validate the effectiveness of the theoretical analysis and the proposed calculation method.