基于正交子空间投影的电力系统同调机群辨识

Estimating Coherent Generators from Measurement Responses in Power Systems Using Orthogonal Subspace Projection

深入剖析了电力系统惯量中心坐标与子空间投影之间的关系,提出一种基于正交子空间投影(OSP)的电力系统同调机群辨识方法。首先,通过OSP获取将电力系统高维广域量测信息投影到各低维子空间的最佳投影方向向量;进一步,借助投影累积贡献率确定最佳投影方向向量数量;然后,根据所确定的最佳投影方向向量划分电力系统的主导同调机群。所提方法计算简单,易于实现,完全基于广域量测信息进行同调分群,可避免模型参数对分群结果的影响,实现同调机群的在线辨识。将该方法应用到典型两区域互联系统和南方电网中进行分析、验证,结果表明,所提方法可准确、有效地从电力系统广域量测信息中快速辨识出系统的主导同调机群。

This paper explores the relationship between the center of inertia(COI)of power system and subspace projection,and proposes an orthogonal subspace projection(OSP)approach to estimate the coherent groups of generators from the measurement responses in bulk power systems.The OSP is first employed to project the high-dimensional measurement response data into low-dimensional subspace to obtain the optimal projection direction vectors.Then,the cumulative contribution rate of projection is used to determine the number of critical optimal projection direction vectors.With the aid of the signs of components in the determined critical optimal projection direction vectors,the dominant coherent groups of generators in the bulk power grids are separated.The proposed approach can avoid the influence of model parameters on the results of coherent groups and is also simple to implement online coherency identification.The simulation data of two-area interconnected system as well as the China Southern Power Grid(CSG)is used to validate the accuracy and effectiveness of the proposed method.The results confirm that the proposed approach can accurately detect the coherent groups of generators from the measurement responses in the bulk power grids.