Metrics for Success: Performance Metrics for Power System State Estimators and Measurement Designs

Power system state estimators (ses) have come a long way since the introduction of the concept nearly four decades ago by Fred Schweppe. Over the years, the concept's initial formulation, implementation techniques, computational requirements, data manipulation and storage capabilities, and measurement types have changed significantly. Today, SEs are instrumental in facilitating the security and reliability of power system operation and play an important role in the management of power markets where transactions have to be carefully evaluated for feasibility and determination of real-time prices. One of the most recent developments in SEs has been the availability of synchronized phasor measurements and their introduction into the state estimation process. Synchrophasor-assisted state estimation (SPASE) is changing the way we view and operate the grid. As such, the ability to monitor and maintain SE performance within known performance standards (metrics) is a new practice. Unlike deterministic applications such as power fl ow, the state estimation solution is not deterministic and depends on the statistical characteristics of the measurements as well as the level of certainty of the assumed network model.