大规模直驱风电场次同步振荡的影响因素分析

针对哈密地区大规模风电场在无串补情况下发生的次同步振荡现象。文中在PSCAD/EMTDC软件上搭建了多机直驱风电场无串补输电系统模型,结合特征值分析法研究了风速、网侧控制器参数、风电汇集点短路比和火电机组出力对次同步振荡特性的影响,并进行仿真验证。结果表明:无串补情况下,风电场在各风段均有可能发生次同步振荡,风速小,振荡频率高,风速大,振荡频率低。网侧控制器比例增益越大,振荡频率越小,积分增益越大,振荡频率越大。短路比越小,系统发生次同步振荡的可能性越大。低功率运行时,火电机组出力在50%~80%范围内,系统发生次同步振荡的可能性最大。

Analysis of Influencing Factors of Subsynchronous Oscillation in Large-scale Direct-driven Wind Farm

In this paper,for large wind farms in Hami area in the series compensated case of subsynchronous oscillation phenomenon,based on PSCAD/EMTDC software,the model of no series compensated transmission system of multi machine direct-drive wind power farm is built,combined with eigenvalue analysis method,the effects of wind speed,parameters of grid-side controller,short circuit ratio of wind power collecting point and output of thermal power unit on the sub-synchronous oscillation characteristics are studied and verified by simulation.The results show that there is no series compensation case,the wind farm may occur in the subsynchronous oscillation in the wind while the wind speed is small,high oscillation frequency,wind speed,low oscillation frequency.The net side controller proportional gain more.Vibration swing frequency is small,the greater the integral gain,oscillation frequency is greater.Short circuit ratio decrease the possibility of system subsynchronous oscillation increases.Low power operation,power units within the range of 50%~80%and the possibility of system subsynchronous oscillation.