近年来海上风电逐渐从近海向深远海开发，形成近海风电场经交流送出、深远海风电场经柔性直流输电送出并在陆上联合接入电网的运行场景。风电交流送出系统与柔直接入系统之间的控制相互作用及其振荡特性值得重点关注。结合某工程实际建立了海上风电交直流联合并网算例系统及其状态空间模型；基于系统线性化状态空间分析了系统主导特征模式及其失稳场景；并通过比较单纯海上风电交流并网或柔性直流并网，以及交直流不同输送容量组合并网系统主导特征模式的变化，揭示了影响海上风电交直流联合并网系统振荡特性的关键因素。最后通过详细电磁暂态仿真验证了分析结果的正确性，研究结论可为海上风电交直流联合并网系统的规划与运行提供参考。

In recent years, offshore wind power development is expanding from nearshore areas to deep-water and far-offshore areas, creating operating scenarios where nearshore wind farms are connected through AC transmission and far-offshore wind farms through VSC-HVDC transmission, with both systems integrated at an onshore grid-connection point. The interaction between AC-connected wind farm and VSC-HVDC converter may affect system oscillatory stability. Based on the actual situation of a certain project, a calculation example system of offshore wind farms integrated with combined AC and VSC-HVDC is established and the state space model of the case system is developed. Based on the linearized state space model, the dominant eigenmodes of the system and their instability scenarios are analyzed. By comparing the variations in the dominant eigenmodes of AC-only, VSC-HVDC-only, and combined AC/VSC-HVDC systems under different transmission-capacity allocations, the key factors affecting the oscillation characteristics of offshore wind power systems with combined AC and VSC-HVDC grid integration are identified. Finally, the correctness of the analysis results is verified through detailed electromagnetic transient simulations. The research conclusions provide guidance for the planning and operation of offshore wind power with combined AC and VSC-HVDC grid integration.