陆上风电全直流发电系统能够有效解决大规模风电并网过程中谐波谐振、无功功率传输等问题，但系统中电力电子设备种类多且各设备的控制耦合复杂，其大扰动下的暂态稳定性机理与传统交流系统不同。为了探究陆上风电全直流发电系统的大扰动稳定性机理，首先，针对“直流汇集—交流送出”方案，基于全直流系统中关键设备的运行特性及控制策略建立了系统等效模型。然后，基于Brayton-Moser混合势函数理论分析了陆上风电全直流发电系统的大扰动稳定性机理，通过求解稳定性判据分析关键参数对系统大扰动稳定性的影响，结果表明系统的稳定性与各变流器的系统参数和控制参数均有关联。最后，基于MATLAB/Simulink搭建仿真模型，验证了理论分析的正确性。

Onshore wind power full DC power generation system can effectively solve the problems of harmonic resonance and reactive power transmission in the process of grid-connected large-scale wind power. But the transient stability mechanism under large disturbances is different from the traditional AC system due to the many types of power electronic devices and the complex control coupling of each device in the system. In order to investigate the large disturbance stability mechanism of onshore wind power full DC power generation system, firstly, the system equivalent model is established based on the operation characteristics and control strategy of key equipment in the full DC system for the scheme of "DC convergence-AC output". Then, based on the Brayton-Moser mixed potential function theory, the large disturbance stability mechanism of the onshore wind power full DC power generation system is analyzed. By solving stability criterion, the influence of key parameters on the system large disturbance stability is analyzed. The results show that the stability of the system is related to both the system parameters and control parameters of each converter. Finally, a simulation model is built based on MATLAB/Simulink to verify the correctness of the theoretical analysis.