WLS distribution system state estimator based on voltages or branch-currents: Accuracy and performance comparison

• Published in: 2013 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) pp. 493 - 498
• Main Authors: Pau, M., Pegoraro, P. A., Sulis, S.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.05.2013
• Subjects: Accuracy; Current measurement; Distribution Networks; Distribution System State Estimator; Estimation; Phase measurement; Phasor measurement units; Smart Distribution Systems; Vectors; Voltage measurement
• ISBN: 9781467346214; 1467346217
• ISSN: 1091-5281
• DOI: 10.1109/I2MTC.2013.6555467

This paper presents a comparison between the two main classes of Weighted Least Squares (WLS) state estimators used in distribution systems: state estimators based on node voltage state variables and estimators based on a state expressed in terms of branch-currents. In particular, the actual accuracy achieved for the estimated quantities by these estimators and their modified versions is analysed in details along with their performance, considering different types of real-time measurements (traditional or phasorial), different configurations of the measurement system and the impact of the network parameters uncertainty. Results obtained on two distribution networks with different scale, 18-bus and 95-bus, are presented and discussed.