Statistical Characterization of Random Errors Present in Synchrophasor Measurements (original) (raw)
Related papers
Impact of the Model on the Accuracy of Synchrophasor Measurement
IEEE Transactions on Instrumentation and Measurement, 2000
Phasor measurement units (PMUs) are becoming one of the key issues of power network monitoring. They have to be able to perform accurate estimations of quantities of interest either under steady-state or transient conditions. Among all the sources which may contribute to the uncertainty introduced by PMUs, this paper analyzes the impact of the phasor estimation models on the accuracy of these devices, focuses on algorithms proposed in the literature for the estimation of dynamic phasors, and studies their performances under several different conditions.
Measurement accuracy limitation analysis on synchrophasors
2015 IEEE Power & Energy Society General Meeting, 2015
This paper analyzes the theoretical accuracy limitation of synchrophasors measurements on phase angle and frequency of the power grid. Factors that cause the measurement error are analyzed, including error sources in the instruments and in the power grid signal. Different scenarios of these factors are evaluated according to the normal operation status of power grid measurement. Based on the evaluation and simulation, the errors of phase angle and frequency caused by each factor are calculated and discussed.
IEEE Open Access Journal of Power and Energy, 2021
This short paper investigates distribution-level synchrophasor measurement errors with online and offline tests, and mathematically and systematically identifies the actual distribution of the measurement errors through graphical and numerical analysis. It is observed that the measurement errors in both online and offline case studies follow a non-Gaussian distribution, instead of the traditionally assumed Gaussian distribution. It suggests the use of non-Gaussian models, such as Gaussian mixture models, for representing the measurement errors more accurately and realistically. The presented tests and analysis are helpful for the understanding of distribution-level measurement characteristics, and for the modeling and simulation of distribution system applications, such as state estimation.
MAPAN, 2019
The technological enhancements and new startups in India have led to a tremendous increase in the power demand. The grids are being made smart, more efficient and reliable to meet not only the growing energy demands but also to prevent blackouts. The synchrophasor technology is evolving, explored and used by the power sectors for real-time measurements with phasor measurement unit (PMU) as the main elemental device. Industries developing PMUs must ensure that it should comply the IEEE C37.118.1-2011 and C37.118.1a-2014 synchrophasor standards, as the corrective action taken by power grid in real-time environment will depend on the PMU data. The optimization of PMU ensures that the measurement results are as per the IEEE synchrophasor standards leading to improvement in its performance. Here, we had evaluated the performance of an industrial PMU using CSIR-NPL PMU calibration system. The evaluation was done under static and dynamic conditions. This analysis represents the capability of PMU testing and calibration at CSIR-NPL and also ensures that the PMU that will be used in real time on the fields reports precise data. PMU-Cal facility can handle all the steady-state and dynamic-state tests for both M class and P class configured PMU at all desired frame rates. This system is traceable to its respective primary standards and is functional to cater the needs of power sector in terms of PMU calibration and testing.
A Statistical Investigation of PMU Errors in Current Measurements
2023 IEEE International Instrumentation and Measurement Technology Conference (I2MTC)
Phasor measurement units are becoming widespread in power systems monitoring. Applications relying on synchrophasor measurements ask for models of measurement errors that can be integrated to describe the uncertainty of the data. In this paper, an assessment of PMU magnitude and phase-angle errors for current measurements is performed for the first time with the aim to address error distributions. In particular, two commercial PMUs are statistically characterized in a controlled environment to prevent non-stationarity issues. It is proven that Gaussianity appears a valid assumption for magnitude errors of both PMUs, whereas phase-angle errors might be non-Gaussian in an accurate PMU when the contribution of synchronization mechanisms prevail.
arXiv (Cornell University), 2018
This letter studies the synchrophasor measurement error of electric power distribution systems with on-line and off-line measurements using graphical and numerical tests. It demonstrates that the synchrophasor measurement error follows a non-Gaussian distribution instead of the traditionally-assumed Gaussian distribution. It suggests the need to use non-Gaussian or Gaussian mixture models to represent the synchrophasor measurement error. These models are more realistic to accurately represent the error than the traditional Gaussian model. The measurements and underlying analysis will be helpful for the understanding of distribution system measurement characteristics, and also for the modeling and simulation of distribution system applications.
Performance evaluation of phasor measurement systems
Power Engineering Society, IEEE General Meeting, 2008
After two decades of phasor network deployment, phasor measurements are now available at many major substations and power plants. The North American SynchroPhasor Initiative (NASPI), supported by the US Department of Energy and the North American Electric Reliability Corporation (NERC), provides a forum to facilitate cultivating the efforts in phasor technology in North America and globally. Phasor applications have been explored and some are in today's utility practice. The IEEE C37.118 Standard is a milestone in standardizing phasor measurements and defining performance requirements. To comply with the IEEE C37.118 and to better understand the impact of phasor quality on applications, the NASPI Performance and Standards Task Team (PSTT) has prepared two comprehensive documents which leverage prior industry work (esp. in WECC) and international experience. The first document describes PMU testing based on both IEEE C37.118 requirements and required dynamic performance tests. The second document describes characterization of PMUs and instrumentation channels based on practical information. This paper summarizes the accomplished PSTT work and presents the methods for phasor measurement evaluation to assure consistent PMU system performance.
On the Accuracy of Phasor Angle Measurements in Power Networks
IEEE Transactions on Instrumentation and Measurement, 2015
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.
Error reduction of phasor measurement unit data considering practical constraints
IET Generation, Transmission & Distribution, 2018
Wide area measurement system relies on phasor measurement unit (PMU) data to monitor, protect, and control highvoltage transmission networks. However, errors in instrument transformers (ITs) located at the inputs of a PMU can significantly degrade its output quality. This study proposes two methodologies for voltage and current transformers calibration using PMU data. The first method calibrates ITs using one good quality voltage measurement located at a tie-line. This method tolerates errors in both the ITs (which are to be estimated) as well as the PMUs. The second method attains the same objective as the first one, with the additional constraint that some portion of the data is unusable. Thus, the second method can be used even when the incoming data is intermittent.