Observability analysis for state estimation using Hachtel’s augmented matrix method

This paper presents algorithms of observability analysis for state estimation when Hachtel’s augmented matrix method is used in the formulation of state estimation. It is shown that the authors’ previously presented algorithms for determining observable islands and deciding multiple measurement placement for gain matrix are ready to be extended to Hachtel’s augmented matrix method, which is commonly used in power networks due to its robustness. Triangular factors updating with multiple rank is also presented, and the updated factors of Hachtel’s augmented matrix can be directly used by state estimator if the real data are used by observability analysis. The proposed algorithms have been tested on IEEE 14 bus and IEEE 118 systems. Numerical examples are provided to illustrate the details of the proposed algorithms. The simplicity and efficiency of proposed algorithms make possible their on-line application for current power networks.