Outlier Suppression and Gross Measurement Tracking Methods in Power System Hybrid State Estimation.

Hybrid estimation architectures make it possible to combine the widespread availability of conventional SCADA data with the improved accuracy and higher sampling rates of synchronized phasor measurements. A particularly appealing hybrid scheme is the so-called APSI architecture, which comprises two sequential estimation stages: a conventional SCADA-based state estimator, whose outcome is then treated as a priori information by a second stage, where available phasor measurements are cumulatively processed. As desirable features, this architecture preserves existing SCADA-based estimators and waives PMU-observability requirements. On the other hand, bad data processing for APSI estimators is a topic that still deserves additional research efforts. In this paper, we set out to improve the resilience of APSI estimators against bad data occurring both within synchrophasor measurements and SCADA data. The proposed strategy comprises two distinct actions: (a) replacing conventional algorithms in the second APSI stage by a more robust one, capable of automatic suppressing outliers in both data classes, and (b) adopting a method for tracing down SCADA gross measurements from a priori data previously identified as erroneous. The performance of the proposed methodology is assessed through tests conducted on the IEEE 14-bus, 57-bus and 118-bus test systems. [ABSTRACT FROM AUTHOR]