On the Accuracy of Phasor Angle Measurements in Power Networks

Abstract

As known, phasor measurement units (PMUs) greatly enhance smart grid monitoring capabilities with advantageous impacts on power network management. Generally, PMUs accuracy is expressed in terms of total vector error, which comprises the joint effect of both angle and magnitude errors, thus possibly concealing the algorithm ability to measure phase. Some recent research works emphasize the importance of measuring current or voltage phasor angle with high accuracy (in the order of a few milliradians) at the distribution level. Because this issue is seldom considered in the literature, in this paper the phase measurement accuracy of three algorithms, namely the basic DFT, the windowed Taylor-Fourier filter, and the interpolated dynamic DFT (IpD 2 FT) estimator, is extensively analyzed by means of simulations performed in various conditions described in the Standards IEEE C37.118.1:2011 and EN 50160:2010. In addition, some meaningful considerations about the uncertainty contributions due to imperfect synchronization are reported.

A Comprehensive Review of Operation and Control, Maintenance and Lifespan Management, Grid Planning and Design, and Metering in Smart Grids

“…The authors present a mixed-integer programming formulation of dynamic state estimation. As Barchi et al [65] and Barchi et al [66] show, the work compares the degree of accuracy of four estimators based on synchrophasors, and they are compared with an estimator based on the Fourier transform.…”

Choice and properties of adaptive and tunable digital boxcar (moving average) filters for power systems and other signal processing applications

“…When a boxcar (or other) filter with fixed length N samples is used within a Discrete or Fast Fourier Transform (DFT or FFT), a technique called the interpolated DFT/FFT [8] was developed in the 1970s, as a post-processing stage to apply, in an effort to reduce spectral leakage, with associated errors and uncertainties. Many modern power-system measurement algorithms continue to apply this technique, or other fixed-window techniques such as Taylor Fourier Transforms or their derivatives [9] [10] [11]. In fields other than power systems, modern literature still suggests that implementing the general digital boxcar filter is difficult, with various techniques suggested to avoid the problem.…”

Fir Filters Compliant with the IEEE Standard for M Class PMU

“…The window (10) has L = 2N + 1 samples. The discrete-time sequence (10) may be used for signal windowing carried out by multiplication or for signal filtering carried out by discrete convolution.…”