Observability analysis and bad data processing for state estimation using Hachtel's augmented matrix method

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

“…Ref. [14] pointed out that, for equations having nearly the same scales, the Hachtel's algorithm is recommended.…”

“…[14] studied the extension of observability theory developed in Refs. [8,9] for the Hachtel's augmented matrix.…”

“…Triangular factorization on the Hachtel's augmented matrix A yields the lower triangular matrix L and the diagonal matrix D where D(28,28) and D(29,29), which correspond to buses 13 and 14, are found to be zero, and the 28th and 29th rows in L −1 are During the process of factorization, pivoting is not needed since injection measurement at bus 1 is linearly dependent of other measurements. From the values in W, we obtain the observable islands: [1,2,3,4,5,7,8,9], [6], [10], [11], [12], [13], and [14]. The irrelevant injections are the ones at buses 5 and 9.…”

“…The observable islands are [1,2,3,4,5,7,8,9], [6], [10], [11], [12], [13], and [14]. The candidates, which can merge observable islands, are the injection measurements at buses 5, 10, 13 and 14.…”

“…Ref. [14] showed that the observability analysis can be carried out in the process of triangular factorization of the augmented coefficient matrix in the Hachtel's method. The theory of numerical observability was extended to the blocked sparse approach in Ref.…”