提出了大规模电力系统小干扰稳定性分析中计算机电振荡模态的一种有效方法。用Jacobi-Davidson方法求取系统状态矩阵按阻尼比递增的特征值子集,抓住了电力系统机电振荡分析问题的本质,避免了大量冗余特征值的计算,大大减少了计算量。另外提出了在Jacobi-Davidson方法中用Arnoldi分解构造初始正交子空间的方法,提高了该方法在迭代初期的计算效率。最后将提出的方法分别在46机和113机系统上进行了试验,结果表明利用所提方法能够有效地求出系统负阻尼和阻尼不足的所有振荡模态,适用于大规模电力系统的机电振荡分析。
The authors propose an efficient method to calculate electromechanical oscillation modes in small signal stability analysis of large-scale power systems. The system state matrix's critical eigenvalues with increasing damping ratios are obtained by Jacobi-Davidson method, which catches the essence of power system electromechanical oscillation analysis, avoids the calculation of a lot of redundant eigenvalues and reduces the calculation amount evidently. In addition, by use of Amoldi decomposition an approach to construct initial orthogonal subspaces is put forward by which the calculation efficiency of Jacobi-Davidson method at the early iteration stage can be improved. The proposed method is tested on 46-machine and 113-machine systems respectively. The results show that by use of the proposed method all electromechanical modes in which the negative damping or unsatisfactory damping exists can be found effectively and this method is suitable to electromechanical oscillation analysis of large-scale power systems.