利用摇摆曲线分析多机振荡

互联多机系统的机电振荡是制约系统稳定运行的一个重要瓶颈,利用摇摆曲线直接提取振荡信息已得到广泛重视。在多机系统中,提取系统振荡信息需要确定在什么曲线上提取。应用EEAC的分群理论把多机系统分成互补的两群,可以显示主导振荡模式的中心位置。EEAC等值机解决了曲线选择的问题,可以提取主导振荡信息。通过改进的多机Prony算法直接对多机曲线进行信息提取,可以更多地反映系统的振荡信息,并且各机组的振荡模态能够显示该机组对振荡模式的参与程度。通过对三机的小系统和华东-福建联网的大系统进行算例仿真可以看出,两种方法都可以提取出弱阻尼或负阻尼的振荡信息。EEAC曲线可以突出主导模式,多机Prony算法可以显示更多振荡模式及其模态。

Using Swing Curves to Analyse Multimachine Oscillations

Oscillation in multi-machine system is an important bottleneck to restrict power system operation.It is broadly recognized that swing curves can be used to distill oscillation information.In multi-machine system,it should be confirmed which curves can be chosen.EEAC theory divides multi-machine system into complementary-cluster,and shows the center of oscillation.EEAC equivalent generator ringdown can be used to distill dominant oscillating information.Through impreved multi-machine Prony algorithm,it can be directly used to distill oscillating information,and mode shape of each generator shows its oscillating degree.The simulation of three-machine system and East China-Fujian power system show that both of two methods can get oscillating information.EEAC curve stands out dominant mode.Multi-generator Prony algorithm can show more modes and their mode shapes.