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Home | Seminars and Symposia | Past seminars/symposia: Tuesday, September 6, 2016

DTC Seminar Series

Linearized Power Flow Modeling for Distribution System State Estimation


Hao Zhu
University of Illinois
at Urbana-Champaign

Tuesday, September 6, 2016
4:00 p.m. reception
4:30 p.m. seminar

401/402 Walter Library

Hao Zhu

Modeling the power network flow and using it for state estimation are among the most classic problems in the field of power systems. Particularly in power distribution systems, these two problems are of growing interest with the ongoing deployment of sensing, communications, and control technologies. This talk will first introduce linear power flow model approximations for multi-phase networks that extend the classical linearized DistFlow (LDF) equations. In particular, we will consider the modeling of line flow difference terms related to power losses, usually neglected by LDF, to develop the Delta-LDF equations. Leveraging this improved linear model, we can cast the state estimation (SE) problem as a quadratic program with linear constraints. The resultant SE enjoys better computational efficiency and numerical stability compared to traditional iterative SE schemes. It is further enhanced with the capabilities of incorporating synchrophasor measurements and low-accuracy pseudo-measurements, as well as estimating the discrete tap positions of voltage regulators. Numerical tests illustrate the performance improvements of the proposed linear power flow models and SE methods using the IEEE 13-bus and 123-bus feeder systems.


Hao Zhu is an Assistant Professor with the Department of Electrical and Computer Engineering at UIUC. She received a BE degree from Tsinghua University in 2006, and MSc and PhD degrees from the University of Minnesota in 2009 and 2012, all in Electrical Engineering. She worked as a postdoctoral research associate on power grid modeling and validation at UIUC’s Information Trust Institute, before joining the ECE faculty in 2014. Her current research interests include power grid monitoring, power system operations and control, and energy data analytics. She received a Seed Grant from the Siebel Energy Institute and the US AFRL Summer Faculty Fellowship in 2016. She is currently a member of the steering committee of the IEEE Smart Grid representing the IEEE Signal Processing Society.