电力系统中非线性奇异现象的研究

STUDY ON NONLINEAR SINGULARITY PHENOMENON OF LOW FREQUENCY OSCILLATION IN POWER SYSTEM

基于低频振荡中的Hopf分歧现象的研究，把发电机的模型扩展到四阶，利用中心流形理论，集中研究了励磁系统参数变化时，系统低频振荡中的非线性奇异现象。研究表明，在各种运行方式下，励磁系统参数变化时，系统出现的都是亚临界分歧，即常规线性化分析所得到的增幅性低频振荡的范围将扩展到S平面的左半平面，稳定域由于亚临界分歧的出现将缩小。

Based on the Hopf bifurcation theory, the nonlinear singularity phenomenon of low frequency oscillation is studied by means of center manifold theory in case the generator model is expanded to the fourth order and the excitation system operating parameters are changed. The result shows that. for different operating points. only the sub-critical bifurcation occurs when the excitation parameters are changed.That is,the growing oscillation for the nonlinear system will be expanded to the left side of plane S and the stability range of the system will be reduced because of the appearance of the sub-critical bifurcation.