METHOD FOR EXPERIMENTAL DETERMINATION OF THE LIQUID DIELECTRIC RESOURCE AND MEASURES FOR ITS RESTORATION

2019 ◽  
pp. 36-41
Author(s):  
S. P. Vysogorets ◽  
A. N. Nazarychev ◽  
A. A. Pugechov
Keyword(s):  
Experimental Determination ◽  
Oil Quality ◽  
Technical Problem ◽  
Transformer Oil ◽  
Quality Stability ◽  
Transformer Oils ◽  
Resource Characteristics ◽  
Theoretical Foundations

The theoretical foundations of changes in the transformer oil quality characteristics, depending on the aging degree, are presented. The introduction of a new indicator of the exploitational transformer oils quality – “stability against oxidation” – is substantiated as a way of solving the scientific and technical problem of assessing the resource characteristics of a transformer insulating system. In order to select the best measures to maintain the quality of power transformers insulating oils, a newly developed “Method for the Experimental Determination of the Luquid Dielectric Resource and Measures for its Restoration” is presented.

scholarly journals Transformer Oil Quality Assessment Using Random Forest with Feature Engineering

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1809
Author(s):  
Mohammed El Amine Senoussaoui ◽  
Mostefa Brahami ◽  
Issouf Fofana
Keyword(s):  
Machine Learning ◽  
Random Forest ◽  
Oil Quality ◽  
Principal Component ◽  
Condition Assessment ◽  
Classification Performance ◽  
Transformer Oil ◽  
Classification Model ◽  
Insulation Degradation ◽  
Transformer Oils

Machine learning is widely used as a panacea in many engineering applications including the condition assessment of power transformers. Most statistics attribute the main cause of transformer failure to insulation degradation. Thus, a new, simple, and effective machine-learning approach was proposed to monitor the condition of transformer oils based on some aging indicators. The proposed approach was used to compare the performance of two machine-learning classifiers: J48 decision tree and random forest. The service-aged transformer oils were classified into four groups: the oils that can be maintained in service, the oils that should be reconditioned or filtered, the oils that should be reclaimed, and the oils that must be discarded. From the two algorithms, random forest exhibited a better performance and high accuracy with only a small amount of data. Good performance was achieved through not only the application of the proposed algorithm but also the approach of data preprocessing. Before feeding the classification model, the available data were transformed using the simple k-means method. Subsequently, the obtained data were filtered through correlation-based feature selection (CFsSubset). The resulting features were again retransformed by conducting the principal component analysis and were passed through the CFsSubset filter. The transformation and filtration of the data improved the classification performance of the adopted algorithms, especially random forest. Another advantage of the proposed method is the decrease in the number of the datasets required for the condition assessment of transformer oils, which is valuable for transformer condition monitoring.

scholarly journals Determination of the technical parameters of shaping tools for delimbing head

2012 ◽  
Vol 58 (No. 4) ◽  
pp. 131-135
Author(s):  
M. Mikleš
Keyword(s):  
Cross Section ◽  
Technical Problem ◽  
Optimal Shape ◽  
Research Attention ◽  
Technical Parameters ◽  
General Curve

It is usually a technical problem to find mathematical ideal shape of knives of delimbing head. Determination of their shape in the form of general curve could lead to the technically unfeasible dimensions of the head. Criterion of the optimal shape of cutting contour of head is tightness of encirclement of cross section of trunk by knives. Research attention was aimed at conics. Parabola is the most suitable curve for achieving the best quality of delimbing.

The Influence of Sampling Frequency on the Results of Motion Analysis Performed by High-Speed Digital Image Correlation

2015 ◽  
Vol 816 ◽  
pp. 397-403 ◽  
Author(s):  
Martin Hagara ◽  
Róbert Huňady
Keyword(s):  
Digital Image Correlation ◽  
Correlation Analysis ◽  
Experimental Determination ◽  
Digital Image ◽  
High Speed ◽  
Sampling Frequency ◽  
Image Correlation ◽  
Correlation System

The paper describes an experimental determination of kinematic quantities using high-speed digital image correlation system. It deals with the analysis of minimal sampling frequency needed for correctly performed high-speed correlation analysis. The authors also describe the influence of cameras sampling frequency on the quality of the obtained results. Mentioned analysis was performed using a rotational object. For the purposes of the results comparison the data obtained from correlation system in a form of displacements in three mutually perpendicular directions were processed in Matlab and in the paper are depicted in a form of graphical visualizations.

scholarly journals Determination of transformer oil quality by the acoustic method

2017 ◽  
Vol 113 ◽  
pp. 01008 ◽  
Author(s):  
Anastasiya Tyuryumina ◽  
Andrey Batrak ◽  
Victor Sekackiy
Keyword(s):  
Oil Quality ◽  
Acoustic Method ◽  
Transformer Oil

scholarly journals Research of thermal stability of the VG transformer oil in the presence of individual sulfides

2018 ◽  
Vol 80 (3) ◽  
pp. 336-340
Author(s):  
L. R. Gaynullina ◽  
V. P. Tutubalina
Keyword(s):  
Thermal Stability ◽  
Negative Impact ◽  
Group Structure ◽  
Optimum Concentration ◽  
Transformer Oil ◽  
Oil Fractions ◽  
Transformer Oils ◽  
Effective Additive ◽  
Thermal Stability Of

In connection with the known negative impact of organosulfur connections on quality of transformer oils and the corresponding rise in price of their production including various ways of cleaning of oil fractions of organosulfur connections re-searches of structural and group structure of oil organosulfur connections and their influence on operational properties of transformer oil have been conducted. Influence of individual sulfides on thermal stability of the brand VG transformer oil in electric field is studied by tension of 30 kV/cm at change of concentration of sulfides in range from 0 to 1,0% from the mass of oil. The research was con-ducted with use of methylbenzylsulfide and a metilfenilsulfide on the basis of the brand VG transformer oil without addition of an ionol. It is established that individual sulfides metilbenzil- and metilfenilsulfide treat the anti-oxidizing additives reducing oil aging speed. For obtaining the maximum thermal stability of transformer oil the optimum concentration of individual sulfides making 0,5% of the mass of oil is defined. The analysis of the inhibiting ability metilbenzil-and a metilfenilsulfida has shown that more effective additive to oil is methylbenzylsulfide which increases thermal stability of oil and reduces amount of the absorbed air more (by 2,2 times) in comparison with the metilfenilsulfide, 0,5% of the mass of oil taken at the optimum concentration equal. The carried-out comparative analysis of a molecular structure of methylbenzylsulfide and metilfenilsulfide has shown that with an identical length of a paraffin chain replacement of a naphthenic cycle by an aromatic kernel leads to decrease in efficiency of individual sulfide as anti-oxidizing additive to oil.

scholarly journals Management of power transformers reliability by technologies of control on resource characteristics of liquid dielectric

2018 ◽  
Vol 58 ◽  
pp. 02007
Author(s):  
Svetlana Vysogorets ◽  
Alexandr Nazarychev ◽  
Ilia Gorec ◽  
Alexey Tadjibaev
Keyword(s):  
Experimental Determination ◽  
Quality Indicators ◽  
Power Transformer ◽  
Liquid Dielectric ◽  
Power Transformers ◽  
Resource Characteristics ◽  
First Time ◽  
The Relationship

The relationship between the resource of a power transformer and the resource characteristics of a liquid dielectric is shown. Determined the key quality indicators, which allow to control the resource of the liquid dielectric. For the first time, “The method of experimental determination of the liquid dielectric resource and measures for its restoration” was developed.

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