A Phasor-Data-Based State Estimator Incorporating Phase Bias Correction

Abstract

With amplitude and phase information, time-synchronized measured phasor data of bus voltages and line currents can be used to calculate, without iterations, the voltage phasor on neighboring buses. In some phasor measurement units (PMUs), it has been observed that the voltage and current phasors exhibit phase biases, which can corrupt the conventional state estimator solution if it is augmented with such biased phasor data. This paper presents a new approach for synchronized phasor measurement-based state estimation, which can perform phasor angle bias correction given measurement redundancy. In this approach, polar coordinates are used as the state variables, because the magnitude and phase are largely independent measurements. The state estimation is formulated as an iterative least-squares problem, and its application to portions of the AEP high-voltage transmission system is illustrated.© 2011 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.QC 2012012

Survey on power system stabilizers control and their prospective applications for power system damping using Synchrophasor‐based wide‐area systems

“…Some of the major applications of WAMS and WACS are the following: event recording [12], real-time monitoring and control [13], phasor-assisted state estimation [14], PMU-only state estimation [15], real-time congestion management [13], post-disturbance analysis [4], [13], system model validation [7] and early recognition of instabilities [11].…”

“…Conventional state estimators (SEs) use data from SCADA with a sampling rate of 1 sample per 4-10 seconds [15] which is too slow to monitor the dynamics of a network. If PMU-only SE is implemented [14], [15], PMUs having a sampling rate between 30-60 samples/s may enhance the observability of system dynamics.…”

“…If PMU-only SE is implemented [14], [15], PMUs having a sampling rate between 30-60 samples/s may enhance the observability of system dynamics. Studies for obtaining dynamic observability from PMU-only state estimation are presented in [75].…”

“…Studies for obtaining dynamic observability from PMU-only state estimation are presented in [75]. A PMU-only state estimator requiring a minimum number of PMUs is illustrated in [15].…”

Tracking network state from combined SCADA and synchronized phasor measurements

“…[3]. For practical reasons, it may be advantageous to leave existing Weighted Least Squares (WLS) state estimator software unchanged and exploit synchronized phasor measurements in a pre-or post-processing step [4], [5].…”