Conventional static state estimation has been the norm in power systems for 40 years. The assumptions and limitations of these SCADA-based processes will be reviewed. The installation of large numbers of synchrophasor measurements made possible by the stimulus program allows a new form of state estimation which overcomes virtually all the limitations of the old technology. The first linear phasor based three phase- state estimator installed on the Dominion Virginia Power 50-kV transmission system as part of a DOE demonstration project led by Virginia Tech will be described. By summer of 2013, a total of more than 600 measurements from 21 500kv stations, five 230kv stations, and one 115-kv station are producing an estimate at a rate of 30 times a second of the three-phase complex voltages on the 500-kV network. The underlying theory, substation architecture, a commissioning process for PMU installation, and techniques to detect bad or missing data and/or switching events, based only on past individual measurements, will be described.
James S. Thorp (LF 2002) was the Kelley Professor of Electrical and Computer Engineering and Department Head Virginia Tech from 2004 to 2009. He was the Charles N. Mellowes Professor in Engineering at Cornell University from 1994-2004 and the Director of the Cornell School of Electrical and Computer Engineering from 1994 to 2001, a Faculty Intern, American Electric Power Service Corporation in 1976-77 and an Overseas Fellow, Churchill College, Cambridge University in 1988. He was elected a Fellow of the IEEE in 1989 and a Member of the National Academy of Engineering in 1996. He received the 2006 IEEE Outstanding Power Engineering Educator Award, and shared the 2007 Benjamin Franklin Medal with A.G. Phadke.