scholarly journals Influencing Factor and Error Analysis of Operating Capacitor Voltage Transformer Harmonic Measurement

2021 ◽  
Vol 2121 (1) ◽  
pp. 012013
Author(s):  
Yan Zhang ◽  
Huajia Wang ◽  
Danwen Yu ◽  
Liu Yang ◽  
Wenjun Cao ◽  
...  
Keyword(s):  
Measurement Error ◽  
Measurement Errors ◽  
Influencing Factor ◽  
Screening Method ◽  
Error Characteristic ◽  
Characteristic Analysis ◽  
Voltage Transformer ◽  
Capacitor Voltage ◽  
The Impact ◽  
Harmonic Measurement

Abstract With the increasing demands of power quality monitoring and management, the problem of harmonic measurement error caused by the widespread operation of capacitor voltage transformers (CVT) in high-voltage power grids has been unavoidable. This paper analyses the influence of environmental factors on harmonic measurement error of CVT, and proposes a new method for analysing the harmonic measurement errors of operating CVT, which explains the unstable phenomenon of CVT measurement errors based on field comparison test, and provides a progressing screening method of effective analysis data. the CVT harmonic error characteristic analysis method proposed in this paper considers the impact of field installation conditions, electromagnetic environment, and other actual operating environment, which can reflect the actual harmonic error characteristics of CVT in field operation. A CVT harmonic measurement system is established based on the proposed method. The validation and effectiveness of the proposed method is illustrated on a field measurements of 1000kV CVT in Shandong Province.

scholarly journals Error Characteristic Analysis of Fluid Momentum Law Test Apparatus

2020 ◽  
Vol 11 (1) ◽  
pp. 90
Author(s):  
Song Yang ◽  
Xianyong Zhu ◽  
Hui Wang
Keyword(s):  
Measurement Error ◽  
Control Method ◽  
Theoretical Research ◽  
Structural Deformation ◽  
Error Characteristic ◽  
Characteristic Analysis ◽  
Jet Impact ◽  
Effect Theory ◽  
Characteristic Points ◽  
Periodic Error

The flat-plate momentum test bench is a widely used experimental device in the verification of the momentum law of fluid mechanics, and its error characteristics are of positive significance for theoretical research and engineering innovation and expansion. The SPH-FEM coupling algorithm and spectrum analysis method are used to calculate and analyze the displacement response and spectrum characteristics of the characteristic points of the sensor under different jet loads. Based on them, the cause, classification, law, scope, influence and control method of the measurement error of the system are discussed and analyzed with the application of the error theory and the lateral effect theory of strain gauges; combined with physical experiments, the relevant analysis methods and conclusions are verified. The results show that the measurement error of the system includes linear error and periodic error. Structural deformation in the direction of jet impact is the main source of linear error; linear error increases with the increase of jet loads. Meanwhile, periodic vibration in non-jet direction is the main cause of periodic error, and the periodic error decreases with the increase of jet loads.

Measurement Error: A Primer for Macroeconomists

2020 ◽  
Author(s):  
Simon van Norden
Keyword(s):  
Measurement Error ◽  
Measurement Errors ◽  
Forecast Errors ◽  
National Accounts ◽  
Simple Arithmetic ◽  
Multiple Data ◽  
Realistic Assessment ◽  
Market Production ◽  
Considerable Controversy ◽  
The Impact

Most applied researchers in macroeconomics who work with official macroeconomic statistics (such as those found in the National Accounts, the Balance of Payments, national government budgets, labor force statistics, etc.) treat data as immutable rather than subject to measurement error and revision. Some of this error may be caused by disagreement or confusion about what should be measured. Some may be due to the practical challenges of producing timely, accurate, and precise estimates. The economic importance of measurement error may be accentuated by simple arithmetic transformations of the data, or by more complex but still common transformations to remove seasonal or other fluctuations. As a result, measurement error is seemingly omnipresent in macroeconomics. Even the most widely used measures such as Gross Domestic Products (GDP) are acknowledged to be poor measures of aggregate welfare as they omit leisure and non-market production activity and fail to consider intertemporal issues related to the sustainability of economic activity. But even modest attempts to improve GDP estimates can generate considerable controversy in practice. Common statistical approaches to allow for measurement errors, including most factor models, rely on assumptions that are at odds with common economic assumptions which imply that measurement errors in published aggregate series should behave much like forecast errors. Fortunately, recent research has shown how multiple data releases may be combined in a flexible way to give improved estimates of the underlying quantities. Increasingly, the challenge for macroeconomists is to recognize the impact that measurement error may have on their analysis and to condition their policy advice on a realistic assessment of the quality of their available information.

scholarly journals Accuracy of single-jet and multi-jet water meters under the influence of the filling process in intermittently operated pipe networks

2017 ◽  
Vol 18 (2) ◽  
pp. 679-687 ◽  
Author(s):  
David Walter ◽  
Miran Mastaller ◽  
Philipp Klingel
Keyword(s):  
Measurement Error ◽  
Measurement Errors ◽  
Distribution Systems ◽  
Air Flow ◽  
Pipe Network ◽  
Filling Process ◽  
Two Phase ◽  
Single Jet ◽  
Water Meters ◽  
The Impact

Abstract In many areas of the world water distribution systems are operated intermittently. The alternate filling and emptying of the pipe network leads to effects, which have negative impacts on water meter accuracy. For example, air that is present in the pipe network due to the emptying process must exit the network during the subsequent filling process. A part of this air is discharged through service connections and, thus, through water meters. In this paper, a study is presented in which the measurement error of single-jet and multi-jet water meters due to the filling process of an empty pipe is investigated experimentally. From the start of air flow to the steady-state flow of water, several causes of measurement errors can be distinguished, such as pure air flow, the impact of the water front on the impeller, the existence of two-phase flow or unsteady flow conditions. For both meter types, it has been discovered that the measurement error is mainly caused by the air flow. The experimental results show that up to 93% of the air volume in the pipe is registered by the water meters. Based on these results, an approach for estimating the measurement error for both meter types is presented.

Detecting measurement error drifts of a capacitor voltage transformer on-line and its field application

2019 ◽  
Vol 30 (10) ◽  
pp. 105109 ◽  
Author(s):  
Chuanji Zhang ◽  
Hongbin Li ◽  
Jian Yang ◽  
Mianzhou Chen ◽  
Yang Jiao
Keyword(s):  
Measurement Error ◽  
Field Application ◽  
Voltage Transformer ◽  
Capacitor Voltage ◽  
On Line

scholarly journals Harmonic voltage measurement error of the capacitor voltage transformer

PLoS ONE ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. e0205231 ◽  
Author(s):  
Jian Le ◽  
Hao Zhang ◽  
Chao Gao ◽  
Qian Zhou
Keyword(s):  
Measurement Error ◽  
Voltage Measurement ◽  
Voltage Transformer ◽  
Capacitor Voltage ◽  
Harmonic Voltage

scholarly journals Selected Aspects of Crisis Management with the Use of Unmanned Aerial Vehicles (UAV) on the Example of a Traffic Disaster

2021 ◽  
Vol 58 (2) ◽  
pp. 140-152
Author(s):  
Wiesław Jaszczur ◽  
Szymon Łukasik
Keyword(s):  
Measurement Error ◽  
Unmanned Aerial Vehicles ◽  
Crisis Management ◽  
Measurement Errors ◽  
The Other ◽  
Research Approach ◽  
Aerial Vehicles ◽  
Other Hand ◽  
The Impact ◽  
Modern Technologies

Purpose: The theoretical aim of this study was to present the impact of modern technologies on the improvement of the effectiveness of process activ- ities (documenting) at the site of a communication disaster. On the other hand, the utilitarian goal was to present the improvement of the organization of documenting a mass incident with the use of drones and photogrammetry tools. Design and methods: As part of the exercise consisting of a simulation of a communication disaster, the activities were documented using the func - tionality of unmanned aerial vehicles which interact with an IT system (Pix4D application). The characteristic drone models which can be used in the monitoring of a disaster site were presented. The discussed research approach describes the methods used to perform drone flights and to what extent the photogrammetric method of processing digital images obtained from drones was used. The issue of field measurements (control points, control lines), the purpose of which was to determine the accuracy of mapping and matching to the coordinate system, was discussed. Results: As part of the research, images were captured and taken with the use of UAVs and IT systems, which were collated and compared with the results of measurements from the visual inspection of the disaster site, performed in a traditional manner by the representatives of the procedural entity. A comparative analysis of the collected research material leading to a comparison of the work results captured by means of the traditional procedural forms with the methods and techniques of modern technologies (drone with the Pix4D Cloud application) allows for the following conclusions to be drawn. For short measuring sections (up to 15 meters), the measurement accuracy of the two methods differs by about 1.5%. For longer measuring sections (up to 100 m), the measurement error is approx. 2.3%. Conclusions: In case of the UAV method and the application Pix4D Cloud, the sources of measurement errors should be seen in the accuracy of rendering of the details of the model (the quality of imaging) and the ability to use this application. On the other hand, when using the police method, in which the measurement trolley is the measuring tool, the sources of error should be seen in the uneven terrain, the obstacles in the terrain, and the measurement error of the tool itself (the trolley). The innovation of the project to use UAVs certainly gains importance especially in a terrain with limited accessibility, i.e. in hilly and mountainous terrain, at road intersections or forks. Keywords: communication disaster, modern technologies, crisis management Article type: preliminary report

Sign in / Sign up

Export Citation Format

Share Document