故障系统低频振荡特征值分析方法

Analysis methods for low-frequency oscillation eigenvalue of faulty system

针对平衡点特征值法不能正确反映故障系统的振荡特性,以及轨迹特征值法窗口宽度难以选择的问题,提出一种适用于分析故障系统特征值的方法。利用共享因子将故障切除后的系统进行等值,再利用原网络及故障分量网络支路电流求取故障后各支路电流及功率,在此基础上,建立系统的等值模型,在各测点处将模型分段线性化,并结合实际受扰轨迹求解故障系统特征值的时间序列。2机和16机系统仿真结果表明,所提方法能实时准确地描述故障系统的时变振荡特性。

Since the equilibrium-point eigenvalue method cannot correctly reflect the oscillation characteristics of faulty system and the trajectory eigenvalue method is difficult to set its window length,an eigenvalue analysis method suitable for faulty system is proposed,which equates the system after fault removing by mutual factor,calculates the post-fault current and power for each branch according to the branch currents of primal power grid and fault component grid,builds the equivalent system model,linearizes piecewise the model at each measuring point,and solves the chronological eigenvalue sequence of faulty system based on the measured disturbed trajectory.The simulative results of 2-generator system and 16-generator system show that the timevarying oscillation characteristics of faulty system are precisely described in real time.