Tutorials: The impact of measurements on power system state estimation

You are here

The impact of measurements on power system state estimation

 Elias Kyriakides

 University of Cyprus



Mihaela Albu 

Politehnica University of Bucharest







Emerging power systems are requiring changes on all layers - planning, operation, markets. Smart grids operation, including control of the energy flow in active distribution grids adds more challenges to the measurement layer. The state estimator constitutes the cornerstone of the Supervisory Control and Data Acquisition (SCADA) system since it provides the power system operating situation in consecutive time intervals. Further, the output of the state estimator is used by other tools responsible for the monitoring and control of the power system. Therefore, there is a need for the power system state estimator to be as much accurate and reliable as possible. The possible sources of uncertainty that may deteriorate the accuracy of a state estimator are the uncertainty in the knowledge of the network parameters and the uncertainty that is encompassed in the measurements. It is well known that the measurement chain is not ideal and this information is passed to the state estimator through the measurement weights.

Modern control algorithms need to process information acquired from distributed, synchronized measurement systems, and embedded in data streams with high degree of correlation. Therefore control requirements represent a true challenge in cases where multiple measurement approaches are used: on one side, the existing time-aggregation based measurements are offered by currently deployed IEDs (SCADA framework), including smart meters and other emerging units; while on the other side, the high-resolution waveform-based monitoring devices like PMUs with fault-recorder functionality.

The tutorial will address:

  • The measurement paradigm in power systems; PQ, SCADA and PMUs
  • Measurement channel quality  Spatial-temporal aggregation of measurement data in WAMS and WAMCS.
  • State estimation (steady state and dynamic)
  • Effect of the measurement weights on the state estimator (considering both the standard uncertainties associated with the measurement devices and the instrument transformers)
  • Impact of measurements on state estimation. 

AUTHOR BIOGRAPHY (Elias Kyriakides)

Elias Kyriakides is an Associate Professor at the Department of Electrical and Computer Engineering at the University of Cyprus, Nicosia, Cyprus. He is a co-founder of the KIOS Research Center for Intelligent Systems and Networks at the University of Cyprus, where he is currently the Associate Director for Research. He has received the Ph.D. degree in Electrical Engineering from Arizona State University in 2003. He is working in the areas of electric power systems and critical infrastructure systems with an emphasis on wide area monitoring and control, power system operations, and renewable energy sources. He has served as a Coordinator for 15 national and European projects and a partner in several others (total funding share over 3 million euro between 2006-2015). He has published two books (Springer, 2015 and Springer, 2016); six book chapters; over 130 refereed journal and international conference publications; and two patents. He has been elevated to a Senior Member in IEEE (2009) and to a Chartered Engineer in IET (2015). He has received several best paper awards and research awards. In May 2009, he was elected the Action Chair of the ESF-COST Action IC0806: Intelligent Monitoring, Security, and Control of Critical Infrastructure Systems (IntelliCIS). He has been invited to present a number of research talks and short courses at various utilities and universities internationally. He has served as an evaluator of proposals (e.g., Belgium, The Netherlands, Greece, Russia, and Estonia), an expert evaluator for business incubator proposals (Republic of Cyprus) and an evaluator for several educational programs. 


Mihaela Albu is a professor of electrical engineering, graduated (1987) from Power Engineering Department of UPB and holds the Ph.D. degree (1998) from the same university. Her research interests encompass wide area measurement systems including synchronized measurements; smart energy grids including optimal use of renewables and real time control; smart metering technologies; DC and hybrid microgrids; power quality and signal processing for power quality assessment, distributed and computer-controlled measurement systems, IEEE and IEC standards in power. Dr. Albu was spending a leave at Arizona State University as a Fulbright Fellow 2002 – 2003 and in 2010. In the past ten years she has been P.I. of more than 20 research projects, funded by national and international research agencies, on various smart grids topics. Dr. Albu is a Senior Member of the IEEE.