Vol 27, No 1 (2019)

Informatics, Computer Science and Control
Well ranking for in-fill drilling using machine learning with production and geological data
Kolesov V.V., Kurganov D.V.
Abstract

In machine learning, support-vector machines (SVM) are supervised learning models with associated learning algorithms that analyze data used for classification analysis. In this paper SVM-rank model is applied for productivity prediction of infill wells for giant Western Siberian oilfield. An essential condition for method’s application is availability of digital databases with representative results which allows adequate model training. Ranking algorithm also uses Voronoi diagram, proven as an approximation to the well drainage area. Complex method allows combine different reservoir and production parameters: productivity and water cut of surrounding wells, frac parameters etc without common reservoir dynamics model, which in this particular case is not able to clarify and confirm the parameters of the reservoir system. There is double model used: the first model utilizes productivity reservoir parameters, the second one uses capacity parameters. The rank of the first model is one of the training options for the second model, and both of them take into account all the geological and production information. The method can be particularly useful in complicated reservoirs, e.g. in dual porosity ones, where the relationship between formation parameters (permeability, porosity, saturation) and production rates is unclear and cannot be set by traditional development analysis, particularly in frac environment.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):6-19
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Probabilistic model of harmonization of the production process with the regional market
Pishchukhin A.M.
Abstract

The market can be considered the brightest representative of stochastic processes. But the production of products also cannot be considered deterministic. Therefore, when managing an enterprise, it is necessary to strive for the harmonization of two stochastic processes. The model of market behavior and the production process was chosen that obeys the Kolmogorov equation. Then, the question was raised - how to manage production: to accelerate or freeze production volumes smoothly, or to apply the quickest possible braking and accelerating of production, following the classical rule - time is money. Using the Euler-Lagrange method, it is shown that the matching of stochastic processes can be reduced in this formulation to a third-order differential equation from the control action in the event of a smooth change. In the case of stepwise application of control actions, the Pontryagin maximum principle is applied to solve the optimal control problem. On the basis of the virtual work concept of control actions, as the work is performed in a larger volume with the most frequently encountered values of market demand, these two methods of control are given to the possibility of comparing the results obtained. As a result, it is shown that for a product with a long production cycle, optimal control, based on the Euler-Lagrange method, has the greatest efficiency, and if the production cycle is short, then control is needed with maximum application of control actions that accelerate or slow down production on the Pontryagin maximum principle. The technique proposed distinguished these two cases even with a rough estimate, which proves its efficiency.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):20-33
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Features of application of hyperexponential and hypererlangian input distributions in queueing systems
Tarasov V.N., Akhmetshina E.G., Othma K.
Abstract

It has been proposed to use two distribution laws of a fairly general form as input distributions for describing queuing systems: hyperexponential and hyperelangian with a wide range of variation coefficients. The main characteristic feature of these laws of distributions is revealed, showing that they can unambiguously be described both by the first two moments and by three moments. The mechanism for their approximation is proposed using the well-known method of moments using both the first two moments and the first three moments. The use of these laws of distributions in the queuing theory extends and complements the well-known incomplete formula for the average waiting time for queuing systems with arbitrary laws of intervals distribution of input requirements and service time. The results obtained are important for modern teletraffic theory.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):34-44
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Instrumentation, Metrology and Informative-measurings devices and systems
Mathematical model of optical chanel of information-measuring fluorometric system
Kulikov V.S., Grishanov V.N., Cherepanov K.V.
Abstract

A mathematical model for evaluation of power of information-measuring fluorometric system is developed. The main objective of fluorimeter is measurement of intensity of fluorescent radiation of human skin in vivo. The model is realized in a packet of computer mathematics Mathcad and consists of the units modeling energetic characteristics of passive optical elements, radiators and photodetectors on base of photometry laws. For creation of model elements reference, literary and experimental data on them are used. Basic purpose of model – operational quantitative comparing of constructive solutions for instrument by energetic criterion – photodiode`s output signal. The given obviously mathematical functions provide openness of model and accessibility for modification by the user.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):45-56
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Modernization of information-measurement system with use of neural network technologies for analysis of electricity balance on Kuibyshev railway
Molochkov A.A., Tyugashev A.A., Frantasov D.N., Kudryashova Y.V.
Abstract

The paper discusses the use of an artificial neural network in an informationmeasuring system for electricity metering to identify and analyze factors affecting the imbalance of electrical energy consumption. The exploited information-measuring systems for commercial metering of electric power of the Kuibyshev Railway are considered. It is established that commercial losses are inherent in the retail market, which is associated with a large number of network connections and the difficulty of identifying unauthorized connections. The problem of measuring losses has been studied and the discrepancy between the accuracy class of the existing measuring equipment at electricity metering points has been revealed. The possibility of increasing the accuracy of metering due to the introduction of a correction device of measuring transducers is considered. An artificial neural network is proposed to be used to identify sections of the network with excessive losses. The structure of the input and output data and the organization of the developed neural network is described. Training of the neural network was carried out on the data on electric power losses at the traction substation "Zhiguli Sea" of the Kuibyshev Railway. The general structure of the information-measuring system for controlling the imbalance of electricity is given. It is shown that the use of neural network technologies can reduce imbalance to 5%.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):57-67
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Using of Chebyshev-Hermite functions for analytical device signals processing
Sayfullin R.T., Bochkarev A.V.
Abstract

The paper deals with the development of theoretical and applied approaches for synthesis fast and compact analytical data processing algorithms which can be used to estimate analytical peaks parameters. These algorithms are based on analytical data decomposition, the Chebyshev-Hermite polynomials are used as decomposition basis. The goal of using data decomposition is possibility of simple estimating of analytical peaks parameters by reconstructing different data transforms directly from decomposition coefficients. These transforms can be obtained by using corresponding bases. In this article considered following bases: basis for reconstruction initial data, bases for reconstruction smoothed first and second derivative of initial data. Examples of using these bases are given. Limitations of this approach are described. Relation between values of decomposition coefficients and modeled analytical peak parameters are obtained, Gauss function used for peak model. The Mathematica 11.3 computer algebra system was used to calculations and graph the results.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):68-81
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Diagnosis of technical means of chronometry based on the analysis of correlation and spectral functions by means of information technology
Yashin V.N., Kolodenkova A.E.
Abstract

The paper deals with the problems of using of correlation and spectral functions apparatus for technical means of chronometry diagnosing as well as using of information technologies for automatization of finding, constructing and analyzing processes of correlation and spectral functions. The paper presents the main approaches to diagnosis of technical means of chronometry, the mechanical chronometer in particular, based on using the correlation and spectral functions apparatus, as well as using information technology to automate the processes of finding statistical characteristics. On the basis of existing methods and means of diagnostics analyzing the diagnostics method of technical means of chronometry is offered. It is based on working out the information models attached to certain defects of the mechanical chronometer.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):82-97
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Electrical Engineering
Scheme design and calculation features of compact windings in ac machines
Grachev P.Y., Tabachinskiy A.S.
Abstract

The paper presents the results of scheme design and overhang deviation calculation for original mass-reduced compact windings of induction and synchronous machines. Electrical equipment of autonomous energy units is among the proposed implementations of these innovative machines. Compact winding’s turns consist of rectangular conductors with periodically irregular cross-section. This solution allows to decrease material intensity and volume of electrical machines due to reduced overhang deviation. Design methodic of three different types of schemes of the stator compact winding - multipolar induction generator winding are given as an example. Calculation features of overhang deviation and copper mass for compact windings are described. Calculation results can estimate the difference between compact and traditional windings.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):98-109
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Mathematical description of mutual influence in a symmetric circuit (lan cable) on the basis of the equation of partial capacities Maxwell
Denisov V.Y., Mitroshin V.N., Chostkovskiy B.K.
Abstract

A brief description of the nature of the influence in symmetrical cables is given. LAN-cable is considered as an object of study. The ideal symmetric circuit is considered. The developed algorithm for obtaining relations describing the mutual influence between the chains for various structural schemes is presented. The mutual effects of two twisted pairs, between the wires of two separate twisted pairs, between four separate twisted pairs are considered. Structural schemes have been built to determine: partial capacities, mutual capacities and capacitive connections. The mathematical description of the mutual influence using partial capacities Maxwell has been received. The results obtained in conjunction with the existing dependences of the cable capacity, the dielectric permittivity of the medium and the wave resistance, which are determined by means of conformal transformations, are the basis for the synthesis of automatic control systems for the technological process of LAN-cable manufacturing.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):110-127
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Algorithm of power line current formation at load node
Kubarkov Y.P., Chivenkov A.I., Vikhorev N.N., Lipuzhin I.A., Shalukho A.V.
Abstract

The paper is devoted to devices and methods for the automated regulation of power flows in the Smart Grids. A description of the method of the current vector control of the power transmission lines electrically combined in a general load power supply system by introducing an additional voltage and applying a line reactor with specified electrical parameters is given. A vector diagram of voltages and currents of the power system is presented, explaining the principles of forming the current parameters of a line reactor installed in an adjustable power line. A virtual tool made in the LabVIEW graphical programming environment based on the CompactRIO platform is described. It is used as an element of a voltage converter control system that implements control of electrical potentials on a line reactor. The effect of the initial phase shift between the voltages of the connected nodes of power lines is observed. The results of the analysis of the voltage vector system in the regulated power system when measuring the initial phase shift between the voltages of power lines and the formation of a predetermined nature of the current of the network choke are shown and the change in the value generated / consumed by the inverter active power voltage is shown.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):128-138
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Modeling of electro-hydraulic processes in a linear asynchronous engine when mixing a melt
Pevchev V.P., Strizhakova E.V., Ovsyannikov V.N.
Abstract

The relevance of the work is due to the need to improve the methods for calculating electromagnetic and hydraulic processes in the melting of an arc furnace for the purpose of reducing energy consumption for mixing metal and increasing the performance of arc furnaces. Objective: analysis of existing methods for calculating electromagnetic and hydraulic processes in the stator-melt system and the development of improved economical options. A set of questions on the modeling of electromagnetic and hydraulic processes in the “statormelt” system in the modes of mixing liquid metal and slag loading is considered. Melt mixing processes occur during the formation of vortices in the horizontal and vertical planes, which affects the requirements for distributed forces in the entire volume of the metal. To improve the efficiency of mixing, a set of modeling problems was considered. Research methods. Calculations of electromagnetic and hydraulic processes in the melt are performed using the finite element method using the Comsol software package. The analysis of the structures of the linear motor stator is carried out to assess the nature of the melt movement and identify the possibility of switching from the mixing mode to the slag loading mode. Taking into account the non-magnetic properties of the furnace body, a simplified geometric model for the coupled electrohydraulic problem, which does not contain the linings and the furnace body, is proposed. The three-dimensional task is implemented for the hydraulic process when defining internal forces in a limited volume, corresponding to the flow of currents in the melt. Results. Numerical models of the electromagnetic and hydraulic processes in the melt were developed, the dependence of the velocity of the liquid metal on the force generated by the engine was determined, the parameters of the models for stationary modes were determined. On the basis of a two-dimensional coupled electrohydraulic model of a melt in a furnace, the distributions of electromagnetic forces and speeds for the modes of metal mixing and slag loading are obtained. Simulation of hydraulic processes in the threedimensional region confirmed the effectiveness of melt mixing in the zone of the frontal parts of the stator winding.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):139-152
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Influence of the pulse-width modulation on the harmonic composition of the output voltage of a frequency converter
Starikov A.V., Lisin S.L., Rokalo D.Y.
Abstract

Currently developed high-speed response digital AC drives, with exceptional ease of technical implementation, which is to minimize the computational procedures. They used frequency converters with trapezoidal output phase voltage, differing in structural simplicity compared with similar devices using the vector principle of voltage generation. At the same time, switching losses in power transistors of such converters are at least 25% less than in analogues with vector modulators. The purpose of the study is to determine the influence of the pulse-width modulation processes on the harmonic composition of the output phase voltage of the frequency converter. The digital modulator which forms a trapezoidal phase voltage by means of the frequency converter on the stator windings of an induction motor is considered. Its main constructive features that can influence on the harmonic composition of the output voltage are determined. To solve of the put problem the decomposition of a piecewise constant function of the output voltage of the frequency converter in the harmonic Fourier series is applied. Analytical expressions for determining of the amplitudes of the fundamental and higher harmonics in the output signal of the frequency converter that forms a trapezoidal phase voltage, taking into account the processes of pulse-width modulation are found. The obtained formulas made it possible to determine the dependences of the higher harmonic coefficients both in the function of the pulse-width modulation frequency and in the function of the frequency of the fundamental harmonic. It is shown that even harmonics and harmonics with the numbers multiple to three are absent in the output signal of the considered frequency converter. The curves of the dependences of the relative values of the odd harmonics coefficients from frequency of pulse-width modulation and frequency of the basic harmonic are constructed. It is concluded that even with allowance of the pulse-width modulation the frequency converter forming trapezoidal phase voltage has small amplitudes of higher harmonics and corresponds to the requirements of the State Standard. Nevertheless, quantitative estimates of the negative effect of the pulse-width modulation process on the output signal of the frequency converter are obtained.

Vestnik of Samara State Technical University. Technical Sciences Series. 2019;27(1):153-166
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