Examination of State of the Cable Insulation by the Return Voltage

2018 ◽  
Vol 19 (6) ◽  
Author(s):  
Dmitry Semenov ◽  
Anna Sidorova ◽  
Pavel Romanov ◽  
Aleksey Kuvshinov
Keyword(s):  
Residual Life ◽  
Technical Condition ◽  
Actual State ◽  
Power Cables ◽  
Insulation Resistance ◽  
Cable Lines ◽  
P Factor ◽  
Paper Insulation ◽  
New System

Abstract The relevance of the study is conditioned by the need to determine the state and residual life duration of high-voltage cable lines to identify faulty and maintainable cables. The aim of the article is to determine a reliable scientifically grounded criterion for assessment of insulation characteristics of the cables in use and to perform a comparative analysis of the results obtained by the traditional method of diagnosing insulation with the results of a new method of assessment by the return voltage. In this regard, the article deals with the issues related to the testing of cables having oil-impregnated paper insulation, as well as with the issue of switching from planned replacement of cables to assessment of their actual state and period of residual life. The authors propose to use the method of examining the cables by the return voltage using the device for testing electrical insulation “UDEI-1” developed at the department of Electrification and Automation of the Nizhny Novgorod State University of Engineering and Economics. The article presents the results of measuring the return voltage of three cables that operated under different conditions. The cables had different technical state. The analysis of the estimation of the residual life of cables by the return voltage was carried out using such criteria as the PIRV polarization index, the LIRV electrical conductivity index, and the P-factor. The P-factor is the physical criterion demonstrating the aging of paper-oil insulation by the shape of the return voltage curve. It represents such characteristics of insulation aging as moistening. To compare the results of testing the cables by the return voltage with the conventional methods of diagnostics and to determine the actual technical condition of power cables, the authors applied the method of spatiotemporal reflectometry and the method of measuring insulation resistance with the determination of such indicators of state as insulation resistance normalized per one kilometer, absorption coefficient, and polarization index. The results of this article confirm that the return voltage gives a qualitative assessment of the state and degree of aging of cables with impregnated paper insulation. The authors proposed a new system for evaluation of cable condition by weighting coefficients. In this approach, the determination of residual life of cables with impregnated paper insulation is based on the values of the return voltage. Application of the new system gives opportunity to improve reliability of the power lines. Recommendations for the further operation of the studied cables are given. The materials of the article are of practical value for carrying out complex assessment of the technical condition of power cables by the return voltage and can be useful for drawing up a schedule for replacement or repair of cable lines depending on their actual state.

scholarly journals Method for the diagnosis of high-voltage dielectric elements during operation based on dynamic registration of electromagnetic radiation

2020 ◽  
Vol 216 ◽  
pp. 01061
Author(s):  
Dmitry Ivanov ◽  
Tatyana Galieva ◽  
Marat Sadykov ◽  
Alexander Golenischev-Kutuzov ◽  
Anatoly Naumov
Keyword(s):  
High Voltage ◽  
Residual Life ◽  
Technical Condition ◽  
Time Of Arrival ◽  
Frequency Method ◽  
Diagnostic Parameters ◽  
Reliable Assessment ◽  
The Difference ◽  
The Moment

Complex remote monitoring and the developed non-contact diagnostic device (NDD) allow monitoring the technical condition and revealing the residual life of high-voltage dielectric elements. It is based on non-contact remote periodic measurement of a set of diagnostic parameters (characteristics of electrical discharges emitted by insulators during operation) necessary for a reliable assessment of the operating state of high-voltage dielectric equipment at the moment of operation and determination of its residual life. NDDs are installed on each phase conductor and used to measure diagnostic parameters, followed by computer processing of the accumulated information signals. An analysis of the set of necessary diagnostic parameters makes it possible to form a conclusion on the degree of performance of dielectric elements. The paper considers a method for detecting defective high-voltage insulators using the developed non-contact diagnostic devices by the radio frequency method and assessing the difference in time of arrival of a partial discharge signal.

Digital assessment of reliability of production system of power subjects

2018 ◽  
Vol 11 (2) ◽  
pp. 109-116
Author(s):  
S. V. Mishcheryakov
Keyword(s):  
Human Capital ◽  
Production System ◽  
Target Function ◽  
Technical Condition ◽  
The State ◽  
Actual State ◽  
Fuel Supply ◽  
Digital Assessment ◽  
Optimal Values

The article outlines scientifi c approaches to the formation of digital technologies for managing the main factors of energy production. The assessment of the state of the production system is based on the index of the state of the production system of the power facility. Its target function is formulated, including dimensionless indices of fuel supply, the state of material and human capital assets. The author has formulated and solved the problem of finding the optimal values of a function using the mathematical apparatus of fuzzy sets. The indices characterizing the factors of production are defined as the solution of the optimization problem using ranking by values and weight coefficients determined by Saaty’s method. The determination of the fuel supply index and the technical condition of assets is carried out on the basis of the methods adopted in the energy sector, taking into account their actual state, provided that the reliability of the functioning of the UES is ensured. The article discusses in detail the technologies for assessing the company's human capital, shows the investment benefits of its development, presents the rational ranges of these investments, and provides statistical data that support the theoretical conclusions.

The Method of Evaluation of the Resource of Complex Technical Objects, in Particular, Aviation

2020 ◽  
pp. 214-230
Author(s):  
Lyudmyla Kuzmych ◽  
Volodymyr Kvasnikov
Keyword(s):  
Residual Life ◽  
Control Object ◽  
Technical Condition ◽  
Actual State ◽  
Production Operation ◽  
Limit Values ◽  
Diagnostic Parameters ◽  
Design Production ◽  
Method Of Evaluation ◽  
Periodic Inspections

The method of estimating the resource of complex technical objects, in particular, aviation technique, is proposed, which includes the construction of a mathematical model of the object's functioning to determine its actual technical condition and residual resource for planning, design, production, operation, repairs, and modernization of aviation technique. To determine the actual state and estimate the residual life of structures, it is proposed to simultaneously evaluate several characteristics of the material of the object: the characteristic parameters of the structure of the material, integral parameters of the material, related to strength (for example, hardness), the presence and nature of macro defects, the degree of corrosion wear of the metal. Limit values of the selected diagnostic parameters are determined by available standards or technical conditions for objects. The dynamics of changes in diagnostic parameters can be monitored and modeled on the basis of the data of periodic inspections of the control object.

scholarly journals Methodology remaining lifetime determination of the building structures

2018 ◽  
Vol 230 ◽  
pp. 02023 ◽  
Author(s):  
Yuriy Otrosh ◽  
Andrii Kovalov ◽  
Oleg Semkiv ◽  
Irina Rudeshko ◽  
Valentin Diven
Keyword(s):  
Structural Damage ◽  
Residual Life ◽  
Technical Condition ◽  
Building Structures ◽  
Design Elements ◽  
Fixed Assets ◽  
Technical Examination ◽  
Effective Use ◽  
Technical Solutions

The paper proposes an approach to determining the increase of the normative lifetime of building structures on the basis of the algorithm of numerical calculation of the residual life of structures, which is performed on the basis of the results of defining parameters obtained during the technical examination and evaluation of defects, failures and structural damage. To calculate the structures, the simulation of the stressstrain state of the building structures with the involvement of OK LIRA was used. Simulation allowed performing optimization of technical solutions and strengthening of structures for buildings. The methodology is used to design elements for strengthening the structures of buildings and structures. Reliable estimation and forecasting of the technical condition enables to prevent the occurrence of accidents of structures and their associated losses, to use rational use of funds for current and capital repairs, and to regulate the technical condition in such a way as to achieve the most effective use of fixed assets.

scholarly journals Transformer lifetime management by analyzing the content of furan and gas dissolved in oil

2019 ◽  
Vol 112 ◽  
pp. 04004
Author(s):  
Irina Alina Chera Anghel ◽  
Elena Gatman
Keyword(s):  
Carbon Oxide ◽  
Technical Condition ◽  
Degree Of Polymerization ◽  
Gas Analysis ◽  
Insulating Oil ◽  
Invasive Test ◽  
Paper Insulation ◽  
Transformer Insulation ◽  
Cellulose Insulation

In order to see the transformer insulation status, the temperature profile, the degree of polymerization (DP), the furan compound content, the carbon dioxide, and carbon monoxide concentration are monitored. By evaluating the degree of polymerization (DP) of the cellulose paper insulation and furans in the determination of the insulating oil, it can estimate the lifetime of the transformer. Analysis of cellulose insulation paper to see the degree of polymerization (DP) can be performed safely only when the transformer is interrupted. However, being a non-invasive test, determination of furane content in an oil-insulating oil is often used as an alternative method for measuring the DP average of insulation paper. In order to analyze the technical condition of a transformer, furan content in oil should be used and interpreted as a primary chemical indicator in conjunction with the results of carbon oxide from the dissolved gas analysis, the acidity and moisture results from the chemical tests, the methanol content from the chromatographic tests and other monitoring techniques.

DETERMINE THE EFFECT OF DESTRUCTION OF ELEMENTS OF THE BASE ON GENERAL TECHNICAL CONDITION OF HOUSING FACILITIES

2014 ◽  
Vol 2 (3) ◽  
pp. 0-0
Author(s):  
Марина Шутова ◽  
Marina Shutova ◽  
Анатолий Субботин ◽  
Anatoliy Subbotin ◽  
Сергей Болдарев ◽  
...  
Keyword(s):  
Construction Projects ◽  
Standard Procedure ◽  
Technical Condition ◽  
Actual State ◽  
Technical Inspection ◽  
Physical Deterioration ◽  
General Technical ◽  
Housing Facilities

The article is devoted compared the results of determination of physical deterioration and condition of foundations housing facilities according to the standard procedure and the actual state of foundations, estimated by the results of a full technical inspection of construction projects

scholarly journals Bridges maintainability evaluation peculiarities as part of hydraulic structures

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Boris Bondarev ◽  
Vladimir Erofeev ◽  
Alexandr Bondarev ◽  
Anastasia Korneeva ◽  
Mihail Gavrilov ◽  
...  
Keyword(s):  
Concrete Strength ◽  
Technical Condition ◽  
Hydraulic Structures ◽  
Actual State ◽  
Final Report ◽  
Shock Pulse ◽  
Structural Elements ◽  
Monitoring Method ◽  
Elastic Rebound

Introduction: the article is dedicated to assessing the condition with respect to use for traffic methods of bridges as part of hydraulic structures (dams, hydroelectric power stations, locks). The main factors affecting the structural element’s durability included in the composition of the hydraulic structures are dynamic loads (applied repeatedly and repeated) affecting the bay due to the hydrodynamic effect; temporary, moving loads from passing highway transportation, along the top of the structure (along the roadway); harmful chemical impurities contained in the water passing through the structure. Under the influence of the above-mentioned factors, defects and damage occur in the hydraulic facilities’ structural elements. Methods: the authors assessed the actual state of the material of the operating structure. To assess structures and materials actual state during the bridge structure inspection work, the following instrumental measurements were performed on as-built structural elements: leveling the top of the sidewalks and the roadway; materials strength determination of the main supporting structures by nondestructive methods; thickness measuring the asphalt concrete pavement of the roadway; determination of the degree of carbonation of concrete; identification of defects in the elements of the bridge. The actual structure’s concrete strength was determined by nondestructive testing methods: (1) by the method of the elastic rebound; (2) by the shock pulse monitoring method; (3) an indirect method of concrete strength ultrasonic testing based on the revealed relationship between the method of separation with shear test and methods – shock pulse and elastic rebound. Results: technical condition and bridge safety indicators calculation as a hydraulic structure element was executed. Discussion: technical examination results of the bridge structural elements and instrumental studies confirm the conclusion about the repair measures need with high-strength concretes and protective coatings based on polymer composite materials. Final report: following the emergency scenarios a numerical estimate table for the quantitative and qualitative parameters list was made, parameters corresponding to a particular structure state. Thus, according to the scenario related to the 3rd accident group, the bridge technical condition is assessed as limited operable, and the safety level is reduced.

scholarly journals Method of operational forecasting the residual life of the brake system elements

2020 ◽  
Vol 17 (1) ◽  
pp. 168-172
Author(s):  
A. G. Kirillov ◽  
◽  
A. S. Ratnikov ◽  
O. P. Kokarev ◽  
◽  
...  
Keyword(s):  
Traffic Accident ◽  
Road Traffic ◽  
Residual Life ◽  
Technical Condition ◽  
Brake System ◽  
Practical Significance ◽  
Brake Pads ◽  
Operational Forecasting ◽  
Brake Discs

The paper considers the method of forecasting failures (replacements) of brake pads and brake discs of KIA RIO cars. At maintenance, especially when independently done by car owners, the technical condition of the specified elements is not correctly estimated, which may lead to the loss of the brake system operability and, as a consequence, to a road traffic accident. The proposed method is simple and has practical significance in the operation of cars. Determination of residual life does not require the use of expensive equipment, which indicates its availability both at service stations and in garage conditions.

Signal processing algorithms for multichannel integrated engines complex diagnostics for automobiles and tractors

Trudy NAMI ◽  
2021 ◽  
pp. 6-15
Author(s):  
V. E. Tarasenko ◽  
O. Ch. Rolich ◽  
O. A. Yakubovich ◽  
A. V. Kozlov
Keyword(s):  
Real Time ◽  
High Performance ◽  
Residual Life ◽  
Technical Condition ◽  
Integrated System ◽  
Automotive Engine ◽  
Automotive Engines ◽  
Signal Processing Algorithms ◽  
Qualitative Determination

Introduction (problem statement and relevance). The technical state of machines undergoes changes during their life cycle. The qualitative determination of the technical condition of components, assemblies and systems of engines requires not only the application of modern control methods that provide reliable results, but also the use of high-performance specialized diagnostic equipment for the timely detection of faults to increase the reliability and service life of machines.The purpose of the study was to substantiate the architecture of an integrated system of vibroacoustic and thermal diagnostics, which would make it possible to assess the residual life of systems, assemblies and mechanisms of diesel engines in real time.Methodology and research methods. The modern methods of collection and computer processing of signals from various types of sensors, as well as wavelet functions and digital image processing were used in the study.Scientifi c novelty and results. Algorithms for calculating and processing the analytical ensemble (including scaleograms and histograms) of the data fl ow have been developed and used in an integrated system of complex diagnostics to identify defects in automotive engines and detect the moments of their origin.Practical signifi cance. The proposed algorithms made it possible to diagnose malfunctions and calculate the residual resource of automotive engine units in real time, display the dynamics of signal changes on the display, process user requests and form a protocol for changing the diesel state picture during its operation.

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