双馈风电机组电力系统低频振荡阻尼特性

由于风力发电机组没有功角，采用数学模型方法分析含风电场的电力系统的低频振荡可能会产生一定的误差，提出基于实测信号的随机子空间算法对大规模双馈风机并网后的系统阻尼特性进行了分析.以含完整双馈发电机组动态模型的电力系统为例，分析了含双馈风电机组的电力系统阻尼特性.分析结果表明，随着风电接入容量的增加，阻尼比并非单调变化，而是存在一个最佳风电接入容量；含双馈风机组的电力系统由于装设了高响应速率的电力电子器件——换流器，有利于系统的小干扰稳定；风电场的阻尼特性与风电场接入位置和故障点之间的电气距离有紧密联系.

Low frequency oscillation damping characteristics of power system with DFIG

Because the wind power generators have no power angle and certain errors may exist when the mathematical model method is used to analyze the low frequency oscillation of power system with wind farm, a random subspace algorithm based on the measured signals was proposed and used to analyze the damping characteristics of grid connected power system of large scale doubly fed induction generators (DIFG). With taking the power system including the dynamic model for complete DFIG as an example, the damping characteristics of power system with DIFG were analyzed. The results show that with increasing the wind power integration capacity, the damping ratio does not monotonously change, while an optimal wind power integration capacity exists. Due to the installation of power electronics device, namely converter, with high response rate, the power system with DIFG is beneficial for the small signal stability of the system. The damping characteristics of wind farm are closely related to the electric distance between the integrated location of wind farm and fault points.