Low-cardinality critical k-tuples in measurement sets for state estimation

Measurement redundancy is the fulcrum of the state estimation process. During the real-time operation of power networks, data redundancy may suffer reductions of different degrees, owing to: loss of communication channels; rejection of spurious measurements; unavailability of metering devices; etc. Criticality analysis consists in verifying if a measurement set is deficient in redundancy, for the state estimation attainment. This scrutiny of data is intimately related to the observability analysis and bad data processing functions of state estimators. This paper concentrates on the identification of critical groups of elements (k-tuples) pertaining to a given measurement set. The potential/practical application of the proposed methodology is illustrated by numerical results obtained with the IEEE 14-bus test system.