Observability analysis and restoration for systems with conventional and phasor measurements
Observability analysis and restoration for systems with conventional and phasor measurements
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DOI：
10.1002/etep.1684
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发表时间：
2013-11
影响因子：
2.3
通讯作者：
G. Korres;N. Manousakis
中科院分区：
文献类型：
--
作者：
G. Korres;N. Manousakis
本文提出了一种高效、快速的方法，利用拓扑和数值方法对相量测量单元和常规（SCADA）测量的状态估计进行可观测性分析。功率和电流测量用于构建拓扑流岛，而拓扑流岛又用于构建简化网络和相关增益矩阵。为了建立这个降阶增益矩阵，考虑了边界功率注入和流岛电压相量。通过分析增益矩阵三角分解过程中遇到的支点进行可观察性检查，并通过对其三角因子进行反代，以非迭代方式识别可观察岛。使用与可观测岛屿边界总线的现有和候选功率注入和候选相量测量相关的简化格拉姆矩阵的三角因子，直接提供将使系统几乎不可观测的额外测量。增益矩阵和Gram矩阵的维数分别等于流岛数和边界测量数，即使对于非常大的系统，这一维数也相对较低，这使得所提算法快速且计算效率高。使用IEEE 14和30总线系统来说明所提出算法的步骤。版权所有©2012 John Wiley & Sons， Ltd。
SUMMARY This paper presents an efficient and fast method, using topological and numerical procedures, for observability analysis in state estimation with phasor measurement units as well as conventional (SCADA) measurements. Power and current flow measurements are used to build topologically flow islands that, in turn, are used to construct a reduced network and an associated gain matrix. To build this reduced order gain matrix, boundary power injections, and voltage phasors at flow islands are considered. Observability checking is carried out analyzing the pivots encountered during the triangular factorization of the gain matrix, and the observable islands are identified in a noniterative manner, by performing back substitutions with its triangular factors. Additional measurements that will render the system barely observable are directly provided, using the triangular factors of a reduced Gram matrix associated with existing and candidate power injections and candidate phasor measurements at boundary buses of observable islands. The dimension of the gain and Gram matrix is equal to the number of flow islands and boundary measurements, respectively, which is relatively low even for very large systems, and that makes the proposed algorithms fast and computationally efficient. The IEEE 14 and 30-bus systems are used to illustrate the steps of the proposed algorithms. Copyright © 2012 John Wiley & Sons, Ltd.