用于次同步振荡分析的直驱风电场等值模型

实际风电场具有风电场数量多、运行工况呈分散性等特点，对风电场进行恰当的等值建模具有实际工程意义。针对由电流内环主导的直驱风电场次同步振荡的等值建模问题，参考同步发电机组建模研究工作，结合K-means分群方法与相似变换原理建立多机并联直驱风电场主导振荡特性保持的等值模型。通过改变电流内环控制参数，对比分析详细模型（考虑风机并网台数，集电线路差异）与等值模型振荡特性差异。研究结果表明:基于相似变换原理搭建的直驱风电场等值模型可以准确反映系统主导振荡特性，有效降低模型阶数，提高仿真速度。

Equivalent Model of D-PMSG-based Wind Farm for Subsynchronous Oscillation Analysis

Actual wind farms have the characteristics of a large number of wind turbines and dispersed operating conditions， and it is of practical engineering significance to establish the appropriate equivalent modeling of the wind turbines. Targeting the equivalent modeling of subsynchronous oscillations in direct-drive permanent magnet synchronous generator （D-PMSG）-based wind farm dominated by inner current loop， referring to the research of synchronized generator modeling， the paper establishes an equivalent model for maintaining the dominant oscillation characteristics of multi-machine parallel D-PMSG-based wind farm by combining K-means and similarity transformation principle. By changing the current inner loop control parameters， the oscillation characteristic difference between the detailed model （considering the number of wind turbines connected to the grid and the difference of power collection lines） and the equivalent model is compared and analyzed. The results show that the similarity transformation principle based equivalent model of the wind farm can accurately reflect the dominant oscillation characteristics of the system， effectively reducing the model order and improving the simulation speed.