针对大规模直驱风电机组通过电力电子设备并入弱交流电网引发次同步振荡问题，提出了改进线性自抗扰技术抑制策略。首先，运用谐波线性化法构建了包含直流电压外环、直流电容电压、锁相环环节的直驱风电并网序阻抗模型。基于此模型，利用频域奈奎斯特稳定性判据对直流电压外环、锁相环和电流内环环节的控制参数以及电网短路比参数的变化致使系统失稳的情况展开分析。其次，为了更进一步增强系统抑制次同步振荡的能力以及抗干扰的能力，在传统线性自抗扰模型的基础之上增添微分环节和准比例谐振环节，从而提出了改进型自抗扰控制器模型。最后，经由频域分析和时域仿真的验证结果表明，所提出的策略和传统线性自抗扰技术相较而言，具备更强大的鲁棒性以及抗干扰能力。

In response to SSO (subsynchronous oscillation) issue resulting from the connection of large-scale direct-drive wind turbines to a weak AC grid via power electronic devices, an improved LADRC (linear active disturbance rejection control) suppression strategy was proposed. Initially, the harmonic linearization approach was employed to construct a sequence impedance model for the grid-connected direct-drive wind power system. This model encompasses the DC voltage outer loop, DC capacitor voltage, and PLL(phase-locked loop) components. Based on this established model, the Nyquist stability criterion in the frequency domain was utilized to analyze the scenarios where system instability is induced by the variations in the control parameters of the DC voltage outer loop, the PLL, and the current inner loop, along with the alterations in the grid short-circuit ratio parameters. Subsequently, with the aim of further strengthening the system's capability to suppress subsynchronous oscillations and enhancing its anti-interference performance, a differential element and a quasi-proportional resonant element were incorporated into the traditional LADRC model. Consequently, an improved active disturbance rejection controller model was put forward. Finally, the verification outcomes from both frequency-domain analysis and time-domain simulation demonstrate that, in comparison with the traditional LADRC technique, the proposed strategy exhibits enhanced robustness and anti-interference capabilities.