基于区间模型和二阶摄动理论的低频振荡模态分析方法

Interval Model and Second Order Perturbation Theory-Based Modal Analysis of Power System Low-Frequency Oscillation

针对大规模复杂电力系统运行参数波动较大,低频振荡模态变化情况不易确定的难题,提出利用区间模型和复模态二阶摄动理论分析振荡模态的方法。首先建立不确定信息下振荡模式的频率、阻尼以及参与因子的区间分布模型;然后利用复模态二阶摄动理论评估该模型在运行参数变化区间较大时,系统振荡模式上述特征要素的变化情况。IEEE16机68节点系统的仿真结果表明,即使系统中同时出现多个运行参数变化较大的情况,该方法也能较准确地评估系统的小干扰稳定性能,并可为运行人员提供更加全面的信息。同时,该方法在分析低频振荡模态方面较一阶摄动理论的准确度更高。

In allusion to the difficulty of determining low-frequency oscillation modals under evident fluctuation of operational parameters of large-scale complex power grid,a method is proposed to analyze oscillation modals by interval models and complex modal second-order perturbation theory.Firstly,interval distribution models of frequency,damping and participating factors under uncertain information are built;then the variation of above-mentioned characteristic elements of system oscillation modals under wider varying intervals of operational parameters is estimated by complex modal second-order perturbation theory.Simulation results of IEEE 16-machine 68-bus system show that even though multi operational parameters of large-scale complex power grid vary evidently and simultaneously,the small signal stability performance of the system can be also estimated accurately by the proposed method and more overall information can be provided to operation personnal.Meanwhile,the results of analyzing low-frequency oscillation modals by the proposed method are more accurate than those by the first-order perturbation.