Analysing the Impact of Electrical Displacement and Leakage Currents in Transformer Insulation on Voltage Measurement Accuracy

2015 ◽  
Vol 792 ◽  
pp. 220-229 ◽  
Author(s):  
Vladimir Lebedev ◽  
Andrey Yablokov

The article examines the methods of calculating capacitive currents in a measuring transformer based on a resistive voltage divider. The developed methods may be used to optimize the design of resistive dividers.

2011 ◽  
Vol 317-319 ◽  
pp. 992-995
Author(s):  
Ying Jun Sang ◽  
Xue Liang Huang

In this paper, the piezoelectric ceramic electronic voltage transducer principles is researched, a new internal structure of the measurement system is put forward and the signal processing methods are discussed. On the basis of the analysis of freedom cantilever optical measurement methods for the longitudinal piezoelectric deformation, we proposes the piezoelectric resonance method to detect amplitude of piezoelectric ceramic and cleverly designed mechanical structure, in which the lightweight elastic material is used to support the resonance thin film. This structure overcomes the impact of cantilever longitudinal self-gravity and horizontal friction between cantilever and piezoelectric ceramic, and can improve the deformation measurement accuracy. 10kV 0.05 class transducer voltage measurement accuracy is achieved theoretically.


Methodology ◽  
2007 ◽  
Vol 3 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Juan Ramon Barrada ◽  
Julio Olea ◽  
Vicente Ponsoda

Abstract. The Sympson-Hetter (1985) method provides a means of controlling maximum exposure rate of items in Computerized Adaptive Testing. Through a series of simulations, control parameters are set that mark the probability of administration of an item on being selected. This method presents two main problems: it requires a long computation time for calculating the parameters and the maximum exposure rate is slightly above the fixed limit. Van der Linden (2003) presented two alternatives which appear to solve both of the problems. The impact of these methods in the measurement accuracy has not been tested yet. We show how these methods over-restrict the exposure of some highly discriminating items and, thus, the accuracy is decreased. It also shown that, when the desired maximum exposure rate is near the minimum possible value, these methods offer an empirical maximum exposure rate clearly above the goal. A new method, based on the initial estimation of the probability of administration and the probability of selection of the items with the restricted method ( Revuelta & Ponsoda, 1998 ), is presented in this paper. It can be used with the Sympson-Hetter method and with the two van der Linden's methods. This option, when used with Sympson-Hetter, speeds the convergence of the control parameters without decreasing the accuracy.


2017 ◽  
Vol 921 (3) ◽  
pp. 7-13 ◽  
Author(s):  
S.V. Grishko

This paper shows that the accuracy of relative satellite measurements depend not only on the length of the baseline, as it is regulated by the rating formula of accuracy of GNSS equipment, but also on the duration of observations. As a result of the strict adjustment much redundant satellite networks with different duration of observations obtained covariance matrix of baselines, the most realistic reflecting the actual error of satellite observations. Research of forms of communication of these errors from length of the baseline and duration of its measurement is executed. A significant influence of solar activity on accuracy of satellite measurements, in general, leads to unequal similar series of measurements made at different periods, for example, in the production of monitoring activities. The model of approximation of the functional dependence of accuracy of the baseline from its length and duration of observations having good qualitative characteristics is offered. Based on the proposed model, we analyzed the dynamics of changes in measurement accuracy with an increase in observation time.


2013 ◽  
Vol 345 ◽  
pp. 251-254
Author(s):  
Yan Jun Zhao ◽  
Shou Guang Cheng ◽  
Bin Qu

NDIR is one of the NO2 concentration measurement methods. The NO2 concentration can be figured out by measuring the attenuation of the infrared light intensity on the characteristic wavelength. But the infrared light intensity is also attenuated by the monodispersion soot particles because of the particles absorption and scattering. So the monodispersion soot particles can impact the NO2 concentration accuracy. The interference of the monodispersion particles is discussed in the paper. Simulation results show that the impact parameters on the NO2 concentration accuracy include the received scattering angle range, particle size and concentration. The solution method is brought out and NO2 concentration measurement accuracy can be improved.


2012 ◽  
Vol 424-425 ◽  
pp. 1253-1257
Author(s):  
Xing Qiao Liu ◽  
Peng Zhang

In this paper, the scattering measuring principle of turbidity is introduced firstly. The new type of turbidity sensor probe designed in this paper overcomes the deficiencies of existing technologies, which has higher sensitivity, strong anti-interference and can detect the turbidity accurately and continuously. The system designed with the core of MCU C8051F020 is presented. Then the design of turbidity sensor probe, data acquisition, processing and non-linear compensation are introduced in detail. Besides, in order to eliminate the impact of temperature on the turbidity measurement and improve the measurement accuracy, temperature measurement circuit has been designed. Test results have shown that the designed on-line turbidity-meter has some advantages: low price, high precision, easy operation etc. It can be widely applied in the fields of waterworks, industrial production, aquaculture, environmental protection and so on


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