永磁风电场经弱交流系统并网的次同步振荡分析

Subsynchronous Oscillation Analysis of Permanent Magnet Wind Farm Connected to a Weak AC System

针对永磁风力发电机组接入弱交流系统时,将会引起次同步振荡问题,通过对电力系统的等值阻抗传递函数进行泰勒展开,提出一种定量计算永磁风机接入弱交流系统引起次同步振荡的分析方法。根据永磁风机接入弱交流系统的特性建立全系统数学模型,计算整个电力系统的等值阻抗,基于等值阻抗传递函数进行泰勒展开,分析泰勒展开式的特征,定量计算次同步振荡的阻尼和频率。最后,在MATLAB/Simulink软件中,利用时域分析法检验此方法的有效性和准确性。

When the permanent magnet synchronous generator is connected to the weak AC system,the subsynchronous oscillation problem will be caused.A Taylor expansion was performed on the equivalent impedance transfer function of the power system,and a quantitative calculation of subsynchronous oscillations when the permanent magnet synchronous generator was accessed to a weak AC system was proposed.The whole system mathematical model was established according to the characteristics of the permanent magnet synchronous generator connected to the weak AC system.The equivalent impedance of the whole power system was calculated.The Taylor expansion was performed based on the equivalent impedance transfer function,and the characteristics of the Taylor expansion were analyzed.The damping and frequency of the synchronous oscillation were calculated quantificationally.Finally,in the MATLAB/Simulink software,the validity and accuracy of this method were tested by time domain analysis.