A Fast and Robust Linear State Estimator for Very Large Scale Interconnected Power Grids

This paper presents a computationally efficient and statistically robust linear state estimator for very large scale interconnected power grids that are made observable by synchronized phasor measurements. The developed estimator has some desirable properties such as robustness against gross errors in phasor measurements (bad data), computational performance that remains minimally affected by growing system size or bad data as long as the size of the largest control area remains bounded, and the fact that independent system operators associated with control areas do not have to share majority of their real-time data or measurements while the estimator solves for the entire system. The estimator is implemented and tested on a small (30-bus) and a large (2917-bus) utility test systems and results are provided.