大区联网条件下四川电网低频振荡分析

针对川渝、华中、华北、山东等电网的互联，求出了与四川电网相关的系统主导低频振荡模式，研究了区域电网互联出现的低频振荡问题。分析了区域间弱阻尼低频振荡模式及发电机在振荡中的作用。利用Prony分析方法检测出了这些主振模式，验证了小干扰稳定分析的正确性。用数值微分方法计算了系统某些运行参数对系统主导振荡模式的灵敏度，分析了这些参数在小干扰稳定中的作用。研究了电力系统稳定器对系统主导振荡模式的阻尼作用。

Analysis of Low Frequency Oscillation for Sichuan Power Grid in Large Scale Interconnected Power Systems

According to the interconnection of power grids such as Sichuan and Chongqing power grid,Central China power grid,North China power grid and Shandong power grid,the dominant low frequency oscillation mode related to Sichuan power grid is solved and the low frequency oscillation under the interconnection of large-scale power grids is researched. The inter-area low frequency oscillation with weak damping and the effect of generators during the oscillation are analyzed. By use of Prony analysis these main oscillation modes are detected and the correctness of small signal stability analysis is verified. The sensitivity of some system operation parameters to system main oscillation mode is calculated by numerical differentiation,the effect of these parameters in small signal stability is analyzed. Besides,the effect of power system stabilizer(PSS) in enhancing the damping during dominant low frequency oscillation mode of power grid is researched.