Power grids are monitored by a mixed set of measurements provided by the Supervisory Control and Data Acquisition (SCADA) system and phasor measurement units (PMU). While SCADA scans are taken typically every few seconds, PMU measurement scan rates can be much higher, such as 30 times a second. In addition to having higher scan rates and being fully synchronized, PMU measurements also facilitate efficient implementation of robust state estimation methods for tracking system states. These robust estimation methods are not new but have so far not been widely adopted by the industry due to their computational disadvantages when applied to SCADA measurements. One important advantage of using phasor measurements is the easy transformation of leverage points by simple scaling. In the absence of leverage points an L1 estimator for PMU-based state estimation can provide a more robust and computationally competitive alternative. Such an estimator is developed and tested first using only PMU measurements. It is then merged with existing SCADA-only estimator to design a mixed SCADA-PMU measurement based estimation procedure which provides improved visibility for the state of the power grid in between SCADA scans even when a small number of PMUs are actually installed in the system. Presentation includes numerical examples to illustrate the discussed procedures and proposed solutions when applied to typical power systems.
Ali Abur obtained his B.S. degree from Orta Dogu Teknik Universitesi, Ankara, Turkey in 1979 and M.S. and Ph.D. degrees from The Ohio State University in 1981 and 1985 respectively. He was a faculty member at Texas A&M University until November 2005 when he joined the faculty of Northeastern University as a Professor and Chair of the Electrical and Computer Engineering Department. His research and educational activities have been in the area of power systems. He is an IEEE PES Distinguished Lecturer and a Fellow of the IEEE for his work on power system state estimation. He co-authored a book and published widely in IEEE journals and conferences. He was on the Editorial Board of IEEE Transactions on Power Systems and Power Engineering Letters during 1999-2011.