Network branch parameter validation based on a decoupled State/Parameter Estimator and historical data

This paper proposes an efficient off-line approach for dealing with power network branch parameters errors, that comprises three phases. In Phase 1 the branches suspected to be with errors are identified through an identification-index vector (IIV), where each element of IIV is the ratio between the number of measurements incident to each branch, whose normalized residuals are larger than one specified threshold value, and the total number of measurement incident to each branch of the network. Using several measurement snapshots, the suspicious branches parameters are estimated, in a sequential form, in Phase 2. In order to do that, it is proposed a decoupled augmented state estimator which increases the V-thetas state vector for the inclusion of suspicious branch parameters. Phase 3 enables the validation of the estimative obtained in Phase 2, via a conventional weighted least squares state estimator. Several simulation results (with the IEEE 14, 30 and 57 bus systems) have demonstrated the high correctness and reliability of the proposed approach to lead with single and multiple parameter errors in adjacent and non-adjacent branches. The results obtained by the proposed approach were compared with those obtained by other existing methodology.