scholarly journals An innovative method of fault detection in power transformers

Author(s):  
Vladimir Mikhailovich Levin ◽  
Ammar Abdulazez Yahya

The Bayesian classifier is a priori the optimal solution for minimizing the total error in problems of statistical pattern recognition. The article suggests using the classifier as a regular tool to increase the reliability of defect recognition in power oil-filled transformers based on the results of the analysis of gases dissolved in oil. The wide application of the Bayesian method for solving tasks of technical diagnostics of electrical equipment is limited by the problem of the multidimensional distribution of random parameters (features) and the nonlinearity of classification. The application of a generalized feature of a defect in the form of a nonlinear function of the transformer state parameters is proposed. This simultaneously reduces the dimension of the initial space of the controlled parameters and significantly improves the stochastic properties of the random distribution of the generalized feature. A special algorithm has been developed to perform statistical calculations and the procedure for recognizing the current technical condition of the transformer using the generated decision rule. The presented research results illustrate the possibility of the practical application of the developed method in the conditions of real operation of power transformers.

Author(s):  
А. A. Yahya ◽  
V. M. Levin

The article considers the method of forming a statistical Bayesian classifier in relation to the problems of operational diagnostics and rapid evaluation of the technical condition of transformer equipment. It is proposed to use the classifier as a regular means to improve the reliability of defect recognition in power oil-filled transformers based on the analysis of dissolved gases in oil. A stochastic approach to the formation of the classifier in a conditions linearly realized dichotomy of technical status classes is developed. As a distinguishing feature, a nonlinear function of the primary parameters of state is used. This simultaneously achieves both a reduction in the dimension of the feature space and an improvement in the characteristics of the random distribution. The proposed approach allows to form a decisive rule that minimizes the total error of decision-making regardless of the impact on the object of random operational factors. The results of the study of stochastic properties of the distributions of the distinguishing feature for each of the selected classes of states are obtained. The algorithm to perform statistical calculations and procedures for recognizing the current state of the transformer using the generated decision rule is designed. The results of the study illustrate the possibility of practical application of the developed approach in the real exploitation of power transformers.


2021 ◽  
Vol 2131 (5) ◽  
pp. 052049
Author(s):  
V Z Manusov ◽  
M R Otuzbaev ◽  
M A Scherbinina ◽  
G V Ivanov

Abstract Assessment of the current technical condition is an important task, so the state of electrical equipment depends on its further operability. Thanks to modern computing devices, it is possible to implement actively artificial intelligence and computer-assisted learning methods that allow achieving high efficiency in data processing. A study was conducted and an algorithm for diagnosing the technical condition based on an artificial neural network was developed. A model based on a multilayer perceptron is proposed, which allows evaluating the technical condition of a high-voltage power transformer. The result of the technical diagnostics of the model is the assignment of the condition to one of the five classes, proposed by the guidelines presented by the International Council on Large Electrical Systems. The methodology is presented on the example of a 250 MVA transformer with a certain defect history, which allowed us to show the reliability and validity of the obtained results. It is shown that the use of the proposed model makes it possible to achieve accuracy in determining the technical condition of 0.95. The introduction of this model into an automated monitoring and diagnostics system will allow assessing the technical condition of electrical equipment in real time with sufficient accuracy.


2020 ◽  
Vol 1 (14) ◽  
pp. 147-156
Author(s):  
Anatoliy Cherepanov

The article notes that reducing the risk due to destruction is possible by an a priori assessment of the maximum technical condition and the degree of degradation of the material of the technical device. The idea is to use a priori information about the technical condition and degradation processes that cause a decrease in strength and a decrease in resource. The application of numerical indicators of corrosion, corrosion resistance of materials, the degree of wear and reserve strength, defects, the risk of destruction and the effectiveness of technical diagnostics at any stage of the life cycle of a technical device is shown. The justification of the model of transition to the limit state is given. Numerical indicators of corrosion, corrosion resistance of materials, the degree of wear and reserve strength, defects, and the risk of destruction are applied. The possibility of developing recommendations for repair, strengthening or replacement of worn-out elements of individual and unique technical devices of various designs is shown.


Author(s):  
Vladimir Levin ◽  
◽  
Nikolay Guzhov ◽  
Natalya Chernenko ◽  
Ammar Yahya ◽  
...  

An innovative methodology for managing repairs in distribution networks and power supply systems for oilfield facilities is proposed in this paper. The methodology makes it possible to select optimal solutions in accordance with the priority management goal by formalizing a risk-based model for planning maintenance and repair (M&R) of electrical equipment with a "condition-based maintenance" strategy. One of the main options in the complex of M&R management tasks is an adaptive model of the technological map for the repairs of power facilities, formed in compliance with a number of key principles. The developed model allows you to optimize the volume and complexity of repairs of electrical equipment of a certain type based on the minimum composition of technological operations necessary to eliminate the identified defects. Detection of defects in electrical equipment is achieved by using methods of technical diagnostics and non-destructive testing. In this case, each of the defects is recorded in the defect statement for the object, with the determination of the degree of criticality and fixing a specific type of corrective action. Optimal prioritization of electrical equipment repairs is performed in accordance with the minimum risk function under current restrictions on reliability (an equipment technical condition index) and available resources (total maintenance costs). The originality of the implementation of a key risk event – a power supply failure of an oilfield facility provides calculating the probability and severity of the consequences of an electrical equipment failure taking into account its technical condition and features of the power supply scheme. The given example illustrates the effectiveness of the proposed approach and emphasizes the validity of optimal decisions. The key components of the developed methodology have found practical application in the conditions of real operation of the equipment of oilfield facilities.


2019 ◽  
Vol 114 ◽  
pp. 04005
Author(s):  
Ngo Van Cuong ◽  
Lidiia I. Kovernikova

The parameters of electrical network modes often do not meet the requirements of Russian GOST 32144-2013 and the guidelines of Vietnam. In the actual operating conditions while there is the non-sinusoidal mode in electrical networks voltage and current harmonics are present. Harmonics result in overheating and damage of power transformers since they cause additional active power losses. Additional losses lead to the additional heat release, accelerating the process of insulating paper, transformer oil and magnetic structure deterioration consequently shortening the service life of a power transformer. In this regard there arises a need to develop certain scientific methods that would help demonstrate that low power quality, for instance could lead to a decrease in the electrical equipment service life. Currently we see a development of automated systems for continuous monitoring of power quality indices and mode parameters of electrical networks. These systems could be supplemented by characteristics calculating programs that give out a warning upon detection of the adverse influence of voltage and current harmonics on various electrical equipment of both electric power providers and electric power consumers. A software program presented in the article may be used to predict the influence of voltage and current harmonics on power transformers.


2021 ◽  
pp. 41-45
Author(s):  

The hydraulic drive of a construction machine is a complex dynamic system that is subjected to many dynamic loads of a variable nature and operates under conditions of variable external influences caused by various factors. During operation, these loads cause failure of the hydraulic transmission elements. To prevent these malfunctions, technical diagnostics should be applied by determining their current technical condition and remaining service life. The article assesses the working condition of hydraulic cylinders using a mathematical model. Using matlab/simulink software to simulate the hydraulic cylinder and hydraulic piston speed when changing the hydraulic cylinder clearance. The simulation results are presented. Keywords: diagnostic, hydraulic cylinder, simulation, development


Author(s):  
N.A. Makhutov ◽  
◽  
A.P. Cherepanov ◽  
M.V. Lisanov ◽  
◽  
...  

Development and practical implementation of the enterprise industrial safety management system considering the new requirements of the legislation on creation of the state system for monitoring, remote control, technical certification, and diagnostics of technical devices at hazardous production facilities supervised by Rostechnadzor is discussed in the article. To perform automated collection, recording, generalization, systematization, and evaluation of the information on the parameters that characterize safety of the enterprise hazardous equipment as a whole and each technical device, a block diagram of the enterprise automated industrial safety management system is proposed. The basics are suggested for creating the automated system containing a database that includes all the technical documentation, certificates and expert opinions, repair documentation and accompanying documents (orders, instructions, audit conclusions, etc.) for the efficiency of tracking the technical condition in real time considering changes in all the controlled parameters of the enterprise technological complexes. It is noted in the article that the assessment of the technical condition and life of single and unique technical devices that make up the bulk of equipment in hazardous production should be carried out already at the manufacturing stage by combining technical control with technical diagnostics, and their results should be included in the technical passport of the device. The need in this information for the operators is invaluable, especially after working out the manufacturer’s designated period of safe operation and for evaluating the actual technical condition and comparing it with its original, which was documented during fabrication. Data on the initial state allows to qualitatively assess the degradation processes that are developing during operation and consider them when evaluating the life of a technical device and conduct a qualitative audit of the industrial safety management system.


2014 ◽  
Vol 633-634 ◽  
pp. 1140-1147
Author(s):  
Vladimir Alekseevich Sokolov

The article suggests an approach to determine structural elements technical condition, based on the mathematical probabilistic apparatus of technical diagnostics. Diagnostics are performed using probabilistic methods of complex technical systems conditions recognition. Probabilistic parameters are calculated according to Bayes’s rule. The paper shows a diagnostics example of intermediate floor elements and systems in the old urban development building. Both the suggested method and information theory methods are used during diagnostics.


2021 ◽  
Vol 2061 (1) ◽  
pp. 012131
Author(s):  
O N Litskevich ◽  
A P Litskevich

Abstract This article solves the problem of a quantitative assessment of the occurrence of destruction in the intersystem interactions of the transport system and the electrical system of the seaport, in the conditions of the technological process in the seaport, which indicates its significant impact on the electrical system, as a result of which the reliability of the berthing power line is significantly reduced. The intersystem interactions that occur during the implementation of the technological process, as experience shows, are the causes of critical situations that occur at the border of areas of different physical nature, and the consequences are recorded, in the case under consideration, in the electrical system. A mathematical model describing intersystem destruction in quantitative form is presented in this paper using a logical-probabilistic model that reflects internal and external relationships. In the object under study, the destructive cause (collision) and the consequence (accumulation of electrical damage in the insulation of the cable line) are in the same object (the mooring power supply unit), and this is limited to the effects of intersystem destruction. In such a statement, the object of power supply of the technological process and equipment is considered as a composite object containing a cable line and an electric contact column. The problem being formulated is an important and relevant scientific task, which includes not only the question of identifying the causes of increased electrical wear of the power line, but also the development of methods for obtaining quantitative results, and in practical terms also involves the diagnosis of the technical condition of electrical equipment and timely preventive maintenance.


Sign in / Sign up

Export Citation Format

Share Document