随着新能源接入比例的不断提高，电力系统的次/超同步振荡风险加剧，准确评估新能源电力系统的振荡稳定性是保障系统安全稳定运行的关键。本文研究一种基于频域模态分析的新能源电力系统振荡稳定性评估方法，该方法通过建立新能源机组/场站、传输线、同步机、变压器等关键设备和场站的频域阻抗/导纳模型，进而根据实际系统拓扑构建系统级频域网络模型，然后通过求解回路阻抗矩阵或节点导纳矩阵行列式的零点来评估新能源电力系统的振荡稳定性，通过计算弱阻尼振荡模式的节点参与因子矩阵定位系统薄弱点，为振荡抑制措施的实施提供依据。以国内某实际新能源电力系统为例，利用频域模态分析法对新能源接入容量和电网运行工况变化下系统的振荡稳定性进行评估，最后基于PSCAD/EMTDC搭建该系统的时域仿真模型，验证了理论分析的正确性。

The increasing penetration of the renewable energy has increased the risks of the sub/super synchronous oscillations in the power systems. It is critical to evaluate the oscillatory stability of the renewable power systems accurately which could help to ensure the safe and stable operation of the system. A method for evaluating the oscillatory stability of the renewable power systems based on frequency-domain modal analysis was investigated in this paper. First, the frequency-domain impedance/admittance models of the key equipment and stations are established, including the renewable power generators/stations, transmission lines, synchronous generators, transformers, etc. Second, a system-level frequency-domain network model is constructed based on the actual system topology. Third, the oscillatory stability of the renewable power system is evaluated by solving the zeros of the determinant of the loop impedance matrix or the node admittance matrix of the system. And the weak points of the system can be located based on the participated matrix of the weak oscillation mode, which provides the reference for the implementation of oscillation suppression measures. Taking the practical renewable power system in East China as an example, the oscillatory stability of the system under the changing access capacity of renewables and grid operating conditions was assessed using the frequency-domain modal analysis method. Finally, the time-domain simulation model of the actual renewable power system was built in PSCAD/EMTDC to verify the correctness of the theoretical analysis.