A framework for estimation of power systems based on synchronized phasor measurement data

Abstract

Abstract-This paper presents a new approach for synchronized phasor measurement-based state estimation, which starts from the buses with synchronized phasor data and enables highly accurate estimation of portions of the power system with connectivity to these phasor data buses. Observability analysis is used to assemble the buses for this Phasor State Estimator (PSE). The state estimation is formulated as an iterative leastsquares problem, with bus voltage and line current magnitudes and phases as the estimated variables. An important aspect of this formulation is its ability to correct for constant or random phase biases that may exist in some phasor measurement equipment. Beside being a standalone state estimator, the PSE can enhance the reliability of a conventional state estimator. The PSE methodology is demonstrated for a power transfer path in the New York power system. Index Terms-synchronized phasor measurements, phasor state estimation, observability methodologies, measurement placement.

State estimation and bad data processing for systems including PMU and SCADA measurements

“…In [11], the effect of measurement asynchronicity on the state estimation accuracy and the effect of using PMU as well as SCADA measurements are analyzed. In [12] an iterative least square state estimator is formulated, with bus voltage and line current magnitudes and phases as the estimated variables. An important aspect of this formulation is its ability to correct for constant or random phase biases that may exist in some PMUs.…”

Vulnerability Analysis of Wide Area Measurement System in the Smart Grid

“…The relationship between measurements and state variables is non linear and it has to be linearised and then the solution to WLS problem is obtained by using iterative technique. However if a PMU is placed at every bus of the system the relation between measurements and state variables is linear and a non-iterative least square solution may be used to determine the system state [18]. The PMU provides a synchronized measurement of the voltage phasor at a bus and the current phasors through the branches associated incident on it.…”

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

“…The method has also been applied to a transfer path in New York's high-voltage system [16] using real PMU data where we deliberately introduced artificial angle shifts to test our methodology. When angle shifts were introduced, the increase in the number of iterations in the Gauss-Newton method was insignificant.…”

“…These type of phase angle errors have been observed from recorded data in several utilities [15], [16], which may be due to a variety of reasons. Phasor angles are typically computed using some signal processing techniques over one cycle or portions of a cycle to minimize the impact of quantization.…”