bluuebunny/crossref_metadata_2025 huggingface dataset:
Area spectral efficiency and energy efficiency in underlay D2D cellular networks
Authors: Plaza Yalena Narvaez , Cardieri Paulo
Published: December 2020

Device‐to‐device (D2D) communication has attracted a great deal of attention in the last few years due to its potential to enhance wireless network capacity and reduce energy consumption, among other benefits. Here, the problem of maximisation of the performance of a D2D network in a scenario in which D2D users share communication channels with users of a cellular network is investigated. Using stochastic geometry tools, the problems of maximisation of the performance metrics area spectral efficiency (ASE) and energy efficiency (EE) of the D2D network by adjusting the density, transmit power, and link throughput of D2D users are formulated and solved. The maximisation of ASE and EE is performed by imposing that the successful transmission probabilities of both D2D and cellular networks are not below given minimum acceptable levels. Based on the derived formulation, the effects of several parameters on the network performance are assessed. The study shows the existence of three possible operating regimes for the D2D network, according to the behaviours (increasing or decreasing) of ASE and EE when the quality of the D2D links increases.
Global stabilisation for a class of stochastic continuous non‐linear systems with time‐varying delay
Authors: Shao Yu , Xu Shengyuan , Li Yongmin , Chu Yuming , Zhang Zhengqiang
Published: December 2020

This paper studies the problem of global stabilisation for a class of continuous but non‐smooth stochastic non‐linear systems with time‐varying delays. Other than the traditional backstepping recursive control, a concise controller of the nominal system is firstly designed by employing the homogenous domination approach, which overcomes the problem of calculating explosion produced by the diffusion and Hessian terms. Then, by means of an appropriate Lyapunov–Krasoviskii functional and a design parameter, the negative effects of the time delays and non‐linear terms generated in the controller design process are dominated; the global asymptotic stability of the closed‐loop system can be ensured by the simple but effective controller, which provides significant cost savings. Finally, a simulation example is given to demonstrate the effectiveness of the presented scheme.
Exponentially reduced carrier mobility of natural ester via blocking effect of 2D hexagonal boron nitride nanosheets
Authors: Huang Zhengyong , He Gang , Li Jian , Wang Feipeng , Zhang Ruiqi , Yao Degui
Published: December 2020

In this work, the boron nitride (BN) nanosheets were dispersed in natural esters to fabricate the dielectric nanofluid. Microstructures and chemical compositions of the nanosized BN are determined. The stability, viscosity, and thermal conductivity of the BN nanofluid, were obtained. And the dissipation factor, electrical conductivity, and relative permittivity of the BN nanofluid, were measured. The ion mobilities and migrating times of the nanofluid were measured under different volumetric fractions of BN nanosheets and temperatures. Results show that the electrical conductivity and dissipation factor of the nanofluid decreased by 54% and 48% with the addition of only 0.1% of BN nanosheets under 110°C. Both the half‐reduced carrier mobility of the nanofluid and the declined ion concentration by blocking of BN nanosheet contributed to the exponentially reduced electrical conductivity and enhanced dielectric performances of the BN nanofluid. The suppression coefficient k is proposed to quantitatively describe the hinder effect of ion migration in nanofluids by 2D BN nanosheet. Results provide a strategy to design and develop advanced nanofluids with low‐dielectric loss by aids of surface adsorption of ion and steric hindrance of 2D nanosheets.
Closing performances of double‐gap laser‐triggered vacuum switch
Authors: Chen Zhanqing , Duan Xiongying , Liao Minfu , Zhang Hao , Zhang Ming , Zou Jiyan
Published: December 2020

To develop high‐voltage‐pulsed power switches with better performances, a multi‐gap laser‐triggered vacuum switch is proposed in this study. Based on established test prototype for double‐gap laser‐triggered vacuum switch, closing processes of double‐gap laser‐triggered vacuum switch are discussed combined with laser‐produced plasma. Closing performances of double‐gap laser‐triggered vacuum switch under different gap polarity configurations, operating voltages, laser energies and laser split ratios are investigated. Closing time delay characteristics of double‐gap laser‐triggered vacuum switch and single‐gap laser‐triggered vacuum switch are compared later. The test results prove that, affected by the imbalanced developed initial plasma between gaps, double‐gap laser‐triggered vacuum switch with two positive gaps and 1:1 laser split ratio presents best closing performances than other switches. With the rise of laser energy, closing delay time and jitter time of double‐gap laser‐triggered vacuum switch both decrease, while the influences from increasing voltages are weak. Closing delay time of P–P type double‐gap laser‐triggered vacuum switch can be controlled within 103 ± 1.5 ns under 90 mJ laser energy, and it is about 10 ns longer than single‐gap laser‐triggered vacuum switch. For some direct current applications with changing voltage directions, P–N type double‐gap laser‐triggered vacuum switch with 1:1 laser split ratio shows more stable closing performances. In addition, closing performances of double‐gap laser‐triggered vacuum switch can be further improved by optimizing the developments of initial plasma in series gaps.
Breakdown of shield gaps in vacuum interrupters
Authors: Feng Weigang , Liu Zhiyuan , Ma Hui , Geng Yingsan , Wang Jianhua , Li Lalian , Bi Dongli
Published: December 2020

The objective of this paper is to determine how the high‐voltage discharging metal vapour deposited on the nearby ceramic inner surface influences the breakdowns of gaps between centre shield and end shield in vacuum interrupters. Two types of shield materials were selected, namely copper and stainless steel. The end curvature radius of the shield was 3 mm. The distance between the shields could adjust manually from 4 to 8 mm. The distance between the shields and ceramic was 3.5 mm. The negative polarity standard lightning impulse voltage (12/50 μs) was repeated for 900 operations based on an up‐and‐down method. The experimental results illustrated that the metal deposition layer on the inner surface of the ceramic envelope significantly influenced the breakdown voltage of the shield gaps. At a shield gap distance of d = 4 mm, the breakdown voltage of the shield gap increased from an initial lower voltage to the saturation voltage by approximately 200 operations. Then, the breakdown voltage decreased to a lower voltage range during only 50 operations, and the breakdown voltage maintained at this lower voltage range until the end of 900 operations. Furthermore, as the shield gap distance increased from d = 4 to 6 mm and 8 mm, the breakdown voltage also maintained at this lower voltage range. A metal deposition layer was formed on the inner surface of ceramic by repetitive application of the lightning impulse voltage. To analyse the influence of the metal deposition layer, the electric field distributions were calculated for the original vacuum interrupter and the vacuum interrupter with the metal deposition layer on the ceramic inner surface. The simulation results suggested that the metal deposition layer took part in the breakdown path between the shield gaps and deteriorated the insulation performance.
Intelligent fault detection and location scheme for modular multi‐level converter multi‐terminal high‐voltage direct current
Authors: Yang Qingqing , Li Jianwei , Santos Ricardo , Huang Kaijia , Igic Petar
Published: December 2020

In order to overcome the drawbacks of the conventional protection methods in high‐voltage direct current transmission lines, a deep learning approach is proposed that directly learn the fault conditions based on unsupervised feature extraction to the detection and location decision by leveraging the hidden layer activations of recurrent neural network. The deep‐recurrent neural network boosting with the gated recurrent unit compared with the long short‐term memory unit is used by analysing both the signal presented in time domain and frequency domain. The proposed method is tested based on a modular multilevel converter based four‐terminal high‐voltage direct current system. Various faults under different conditions were simulated against fault resistance, external faults and small disturbance immunity with the validity, and the simulation verified a high accuracy, robustness and fast results because of the utilization of characteristic feature extraction.
Research on discharge phenomenon caused by cross‐adsorption of linear insulating fibre and metal dust under DC voltage
Authors: Liang Ruixue , Hu Qi , Liu Heng , Wang Jian , Li Qingmin
Published: December 2020

A large amount of metal dust is often generated during production and operation of Gas Insulated Switchgear/Gas‐Insulated Transmission Line, and insulating fibres are very easy to mix in during assembly. The discharge phenomenon induced by these two impurities remains unknown. By setting up a test rig with parallel electrodes, the discharge characteristics of metal dust and linear insulating fibres under the negative DC voltage were studied separately and jointly. The obtained research results indicate some interesting phenomena that the metal dust may render ‘sand storm’ motion characteristics under the action of the electric field, and the linear insulating fibres appear to show ‘standing’, ‘jumping’, ‘flying fire’ and other phenomena. A small amount of dust and fibres alone present little effect on the breakdown voltage of the air gap. However, while the insulating fibres and metal dust coexist, the metal dust will be adsorbed on the surface of the insulating fibres, then the surface charge of the fibres is reallocated, and the discharge phenomenon at both ends of the fibres is enhanced, so that the insulating fibre exhibits similar movement and discharge characteristics to the linear metal particles. At the same time, the fibres with dust absorbed on will result in an air gap breakdown voltage drop of approximately 25%–40%. What's more, if the discharge of fibres and the ‘sand storm’ movement of the dust coexist, it may directly lead to ‘explosion’ of the moving dust, causing severely ablation of the plate surfaces, and thereby the degree of destruction increases dramatically.
Facial expression recognition using a combination of enhanced local binary pattern and pyramid histogram of oriented gradients features extraction
Authors: Sharifnejad Maede , Shahbahrami Asadollah , Akoushideh Alireza , Hassanpour Reza Zare
Published: December 2020

Automatic facial expression recognition, which has many applications such as drivers, patients, and criminals' emotions recognition, is a challenging task. This is due to the variety of individuals and facial expression variability in different conditions, for instance, gender, race, colour and changing illumination. In addition, there are many regions in a face image such as forehead, mouth, eyes, eyebrows, nose, cheeks and chin, and extracting features of all these regions are expensive in terms of computational time. Each of the six basic emotions of anger, disgust, fear, happiness, sadness and surprise affect some regions more than the other regions. The goal of this study is to evaluate the performance of enhanced local binary pattern, pyramid histogram of oriented gradients feature‐extraction algorithms and their combination in terms of recognition accuracy, feature vector length and computational time on one, two and three combined regions of a face image. Our experimental results show that the combination of both feature‐extraction algorithms yields an average recognition accuracy of 95.33% using three regions, that is, the mouth, nose and eyes on Cohn–Kanade dataset. Besides, the mouth region is the most important part in terms of accuracy in comparison to eyes, nose and combination of both eyes and nose regions.
Infrared small target detection based on non‐convex triple tensor factorisation
Authors: Rawat Sur Singh , Verma Sashi Kant , Kumar Yatindra
Published: December 2020

In the present infrared target detection system, simultaneously achieving both the target detection performance, as well as, computing efficiency is considered as a big task. To, address the above said issue, a non‐convex triple tensor factorisation is incorporated into the existing infrared patch tensor model in the proposed work. In the proposed model (triple tensor factorisation‐infrared patch tensor), local prior information using linear structure tensor and corner strength is incorporated so that the strong clutters in the background can be easily suppressed and the target can be detected correctly. Finally, the method proposed, was solved by alternating direction method of the multiplier. Large number of experiments were conducted and the results presented in the experiments suggest that the method proposed has shown good performance for background suppression, as well as, for the target detection in the clutter environment, when compared with the other baseline methods.
Grading ring parameters optimization for 220 kV metal‐oxide arrester using 3D‐FEM method and bat algorithm
Authors: Alti Nadjim , Bayadi Abdelhafid , Belhouchet Khaled
Published: December 2020

Aging of metal oxide surge arresters is mainly affected by the high electric stress near the high voltage electrode. It has been observed that the distribution of voltage and electric field along an arrester is non‐uniform. In this paper, the effect of grading ring geometrical parameters is investigated in order to achieve a more uniform electric field and voltage distribution. A 3D finite element method was employed based on COMSOL MULTIPHYSICS software to calculate these latter. The optimal design of grading ring is achieved by minimizing the electric field along the active column of varistors using a reduced number of simulations based on the Taguchi design and a bat algorithm. Initially, simulation results for a single grading ring were analysed. By using an optimal design of the single ring, the electric field is reduced by 42% in the top of the 220 kV metal oxide surge arrester and the voltage distribution can be improved. It was proposed to install an additional ring at the top of the metal oxide surge arrester. Simulation results shows that using of an optimal design of grading rings, the distribution of voltage and electric field along the surge arrester can be made as uniform as possible.
Constraining the magnetic field properties of Bok globule B335 using SOFIA/HAWC+
Authors: Zielinski N. , Wolf S. , Brunngräber R.
Published: December 2020

Thanks to their well-defined shape and mostly isolated locations, Bok globules are suitable objects for studying the physics of low-mass star formation. To study the magnetic field of the prototypical Bok globule B335, we obtained a spatially resolved polarization map with SOFIA/HAWC+ at a wavelength of 214 μm. For the first time, these observations reveal that polarization holes in Bok globules, that is, the decrease in polarization degree towards their dense centers, also occur in the far-infrared wavelength regime. The observed polarization pattern is uniform with a mean polarization angle of 48° ± 26° and a magnetic field strength of ~142 μG. Moreover, we use complementary polarimetic data for B335 obtained at near-infrared to millimeter wavelengths to analyze and constrain the magnetic field across different scales. By applying the 3D Monte-Carlo radiative transfer code POLARIS, we developed a model for the density and magnetic field structure as well as for the dust properties of this globule. We conclude that the column density towards the center of B335 is too low to cause the observed polarization hole in B335 via dichroic absorption. Furthermore, we conclude that the effect of self-scattering has no significant impact on the observed polarization. Adopting dust-grain alignment via the radiative torque mechanism, a combination of the interstellar radiation field and the central star as radiation sources is consistent with the decrease in polarization degree at the outer regions of B335 (≈104 au from the core). However, the model fails to explain the low polarization degree within the inner 5000 au.
Features of the FEC functioning modeling for solving the selecting critical facilities problem
Authors: Beresneva Natalia , Pyatkova Natalia
Published: December 2020

The paper presents the system of models for the fuel and energy complex functioning used to determine the critically important facilities, built on the basis of the fuel and energy complex territorial production model of the . A formalized representation of the model is given, a three-stage scheme for working with it is described. For the selection of the fuel and energy complex critically important facilities , the most important and accompanying model indicators are highlighted, an integral indicator of the industry elements criticality is proposed. The results of testing the developed models are presented (illustrative example).
Transformation of corporate governance in the Russia’s electric power industry
Authors: Sheveleva Galina I.
Published: December 2020

To make Russia' electric power industry more appealing for investors, in the course of its reformation its generating assets were privatized with international corporate governance principles adopted. One of the key reasons that hinder the solution of the above problem is the transformation of corporate governance. The results of the assessment of power generating companies' compliance with the Corporate Governance Code in 2017–2018 are presented. The assessment was conducted using the Bank of Russia methodology. An additional analysis of information on general corporate governance practices as retrieved from the official websites of these companies was performed. We took into account the findings of the research published in this area as carried out at St. Petersburg State University, the New Economic School, the Russian Institute of Directors, the Platforma Center for Social Engineering, the MGIMO University, the Independent Directors Association and the HSE University. The key aspects of corporate governance transformation in the Russia's electric power industry were identified by summarizing the data thus obtained. They were primarily limited to claiming a formal approach adopted by majority owners so as to comply with international corporate governance standards in the process of permanent redistribution of ownership and increasing its concentration.
Complex of technical solutions for protection and selective signaling of single-phase earth faults in 6-10 kV distribution cable networks
Authors: Shuin Vladimir , Shadrikova Tatiana , Dobryagina Olga , Shagurina Elena
Published: December 2020

Single-phase earth faults are the predominant type of damage in distribution 6-10 kV cable networks, and are often the root cause of power failures to consumers, accompanied by significant economic damage. Therefore, reliability for about 50% of consumers of industrial and urban power supply systems depends on the technical perfection of protection against earth faults. The currently used approach to the design of protection and signaling of earth faults, based on the application of the existing concept of selectivity of considered protection, does not always ensure the achievement of the main goal – increasing the reliability of power supply to consumers. To improve the reliability of power supply, new technical solutions are needed that provide not only selective detection of the damaged connection for all types of single-phase earth faults, but also the recognition of the most dangerous for the network and the protected connection faults types for automatic selection the most effective protection action (signal or shutdown). Within the framework of the existing approach, the design of protection against earth faults with the specified properties is possible only on the basis different methods of its implementation in networks with different neutral grounding modes, which is associated with the complication of protection circuit, its design and exploitation. A new approach has been proposed that provides universal technical solutions for protection and signaling of earth faults for 6–10 kV cable networks with various neutral grounding modes. To implement the proposed approach, universal adaptive current protection and universal admittance protection based on the control of the capacitance of zero sequence loop of the protected connection have been developed.
Parameter Evaluation Procedure for Gapped Core Current Transformers Considering Accuracy Requirements under Transient Conditions
Authors: Vorobiev Victor , Moskalenko Vadim , Rasshcheplyaev Anton , Nudelman Goda , Navolochny Alexander , Onisova Olga , Naumov Ivan
Published: December 2020

Particular features of gapped core current transformers and characteristics of transient phenomena inside them are under consideration; a procedure is proposed that allows for evaluating the excitation limiting e.m.f. and overall dimensions of the CT required for installation, based on known parameters of the transient conditions in CT installation point and the specified CT error.
Categorization of reliability of electrical appliances based on risk assessment
Authors: Ershov Michail , Komkov Alexander , Melik-Shaknazarova Irena
Published: December 2020

The article proposes a methodology for assigning categories of power receivers according to the requirements of reliability of their power supply. The concept of “category of electrical receiver” is fundamental in relation to ensuring the reliability of power supply and has long been used in general industrial and industry guidance documentation. At the same time, the interpretation of long-formulated formulations regarding the attitude of the receiver to one or another category still remains ambiguous and allows for misunderstandings, which is especially evident in industry documents. In order to formalize the process of assigning a receiver to one or another category, to make it more objective, a technique is proposed that is based on recently actively developed methods of expert risk assessment. The methodology allows, without going over to monetary terms, to qualitatively assess risks and formalize the procedure for establishing the category of a particular electrical receiver. An example of an expert qualitative assessment of risks and the choice of a category of electric drive of a sucker-rod pump installation is given.
Research of the possibility of application of the superposition method for implementation of algorithms for determining damage locations in networks with isolated neutral
Authors: Kulikov A.L. , Osokin V.Ju , Bezdushniy D.I. , Loskutov A.A.
Published: December 2020

It is difficult to develop precise algorithms for determining fault locations for single-phase and double earth faults due to the features of emergency modes in medium voltage networks of 6-35 kV. The arbitrary configuration of electrical networks complicates the development of universal fault locations algorithms and, as a rule, technical solutions are limited by the need to use one-way measurements of emergency mode parameters. The article discusses new topology independent fault location algorithms that involve the use of the superposition method. The application of the proposed algorithms is justified by the results of simulation modeling and will allow implementation of calculating the distance to the fault in networks with isolated neutral with high accuracy.
Innovative X-ray control technology of high-voltage circuit breaker technical condition
Authors: Darian Leonid , Golubev Pavel , Obraztsov Roman
Published: December 2020

The paper presents the results of practical application of an instrumentation and analytical system (IAS) for X-ray control of minimum oil and SF6 circuit breakers. The capabilities of IAS are described and the technology for its implementation is given. It is shown that the proposed technology makes it possible to control the contact group (moving and fixed contacts) and elements of the moving contact control system of circuit breakers without bus bar dismantling, oil drain and disassembly of the circuit breaker poles. The paper also presents the assessment of the reliability indicators of high-voltage circuit breakers, which confirms the prospects for introducing the developed X-ray inspection technology.
Application of IR spectroscopy to control oxidation inhibitor (ionol) concentration in mineral transformer oils
Authors: Garifullin Marsel Sh. , Lyutikova Marina N. , Kuchkarova Adelya R. , Bikzinurov Azat R. , Solobodina Yuliya N.
Published: December 2020

Mineral insulating oils used as dielectric and heat dissipating agent in high voltage oil-filled equipment are subject to oxidation. Oxidation results in the appearance of undesirable substances that reduce the electrical insulating properties of liquids. Therefore, to inhibit the oxidation process, an antioxidant additive is introduced into transformer oils. In the overwhelming majority, 2,6-di-tert-butyl-4-methylphenol (ionol) is used as an inhibitor. Residual concentration of ionol is a regularly monitored parameter. In Russia, the main method for determining the concentration of ionol in oil is gas chromatography. However, fourier-transform infrared spectroscopy should be considered as an alternative method for monitoring the ionol content as it has a number of advantages over the gas chromatographic method. The paper compares the results of the determination of ionol in operational transformer oils using gas chromatography and the IR method. We justified that the method of IR spectroscopy has no limitations as applied to oils from power transformers equipped with adsorption purification systems.
Numerical modeling of combustion of gaseous and solid fuels in the furnaces of small and large boilers to reduce harmful emissions
Authors: Zheltukhina Elizaveta , Pavlova Marina , Ziganshin Malik
Published: December 2020

The issues of the formation of toxic compounds that enter the air of the residential area during the circulation of household waste and the provision of energy supply services, in particular, during the decentralization of heat supply to residential buildings, are considered. The problems of finding the optimal ways to reduce toxic emissions are solved using a numerical experiment based on computational fluid dynamics. The results of numerical modeling of the corresponding combustion device are compared with the geometry created using the Gambit software and in the Solid Edge 3D design environment. The influence of the pressure in the furnace on the characteristics of fuel combustion during operation in the pressurization mode of the recently widespread condensing boilers is given. Acceptable simplifications for the application of the normative method in the calculations of modern combustion devices with a specific geometry are proposed.
Study of the operation of a 110 MW combined-cycle power unit at minimum loads when operating on the wholesale electricity market
Authors: Marin George , Mendeleev Dmitrii , Osipov Boris
Published: December 2020

Currently, all generating equipment with a capacity of more than 25 MW operates in the wholesale electricity market. The operation of combined cycle gas turbines is complicated by the implementation of daily load schedules. A distinctive feature of the operation of combined-cycle units is the presence of a gas and steam turbine in the cycle. In this paper, the variable operating modes of a combined cycle plant are considered. The minimum effective load of a gas and steam turbine is determined. An example of the real operation of a steam turbine that is included in a combined cycle plant 110 MW power unit at an operating combined heat and power is shown. The optimal minimum load of a combined cycle gas turbine unit has been determined. As a result of the research, the values of high and low pressure steam flow rates, fuel gas consumption, steam and gas turbine power were obtained. Based on the research results, the optimal minimum load of a combined cycle gas turbine unit was found - 40 MW. This load allows the main and auxiliary equipment to work without compromising reliability.
Information Security of Power Plants
Authors: Nabiullin Dinar , Vildanov Rustem
Published: December 2020

The article deals with the main problems of the information security of power plants. Possible probabilities of hacker attacks on individual objects in the energy sector have been investigated. Possible attack scenarios and ways to prevent them are also discussed.
Research on energy efficient kinetics of drying raw material
Authors: Safarov Jasur , Khujakulov Akhtam , Sultanova Shakhnoza , Khujakulov Ulugbek , Verma Sunil
Published: December 2020

In this work, at constant values of the process temperature, the kinetics of drying was considered through the Fick diffusion equation with the corresponding initial and boundary conditions. To describe the process with mathematical expressions, Fick’s equation, which expresses the value of moisture content, is reduced to a dimensionless formula. When accepting the boundary conditions of the first kind, the ratio of the moisture diffusion coefficient to the square of the determining size was determined by the least squares method using a special program with subroutines for solving partial differential equations with a sufficient number of exponents in the solution.
Definitions of useful energy and temperature at the outlet of solar collectors
Authors: Sultanova Shakhnoza , Safarov Jasur , Usenov Azamat , Raxmanova Tojiniso
Published: December 2020

The article examines the solar collector of a solar water heating dryer using the example of drying ginger root (Zungiber). The diagram of a solar water heating drying unit is presented. The useful energy and temperature coming from the solar collector were analyzed using the model. The graphs are compared with the experimental results.
Large pumping stations as regulators of power systems modes
Authors: Nurmatov Obid
Published: December 2020

The article discusses the issues of the effective use of synchronous motors installed in irrigation pumping stations. The necessary capacities for water delivery to waterless territories are given. It is shown that synchronous motors can generate reactive power and thus actively participate in the control of the system mode.
Algorithm for optimization of power system short-term mode in conditions of partial uncertainty of initial information taking into account the frequency change
Authors: Gayibov Tulkin
Published: December 2020

Many existing methods and algorithms for optimization of short-term modes of power systems provide in calculations the introduction of a slack bus station, which ensures the balance of active power and, accordingly, the permissible frequency. In cases where the real load deviates from the planned one, determined by forecasting, the power system mode may turn out to be not optimal, and sometimes even not acceptable. This factor is especially noticeable in conditions of partial uncertainty of initial information about loads of nodes. To overcome this problem, planning of power system mode should be carried out taking into account the frequency change and, accordingly, the regulatory capabilities of all stations.

This paper proposes an algorithm for optimization of modes of power systems in terms of partial uncertainty of initial information about loads, taking into account the frequency change. On the basis of computational experiments using the proposed algorithm, it is shown that taking into account the frequency change when planning modes of power systems with partially undefined loads of nodes can give a significant economic effect.
Calculation and study of the magnetic field of the stator winding of a turbine generator
Authors: Mustafakulova Gulzoda , Egamov Akmal , Mirkhonov Utkir , Nizamov Jasurbek
Published: December 2020

An analytical method is presented for calculating the electromagnetic field of the stator winding of an alternating current machine, a turbine generator by solving the Laplace equation, first for a point conductor with a current i, by the method of separating variables when representing the space of the machine location consisting of five regions. The purpose of the work is to show that for all three components of the air gap field created by the winding, the magnetic circuit is common, but the magnetic circuits are different for each of them.
Frequency control of asynchronous motors of looms of textile enterprises
Authors: Pirmatov Nurali , Panoev Abdullo
Published: December 2020

In article are brought frequency regulation of the asynchronous electric motor and that reach to energy saving itself. Frequency management is energy saving so regulation of the frequency of the rotation of the asynchronous engine are provided increasing coefficient of efficiency and reduction of the loss to powers. Frequency management, asynchronous engine, economy to energy, load, loom, activate current, frequency of the rotation of the engine.
Use of maneuverable properties of hydroelectric power plants and hydro-accumulating power plants for improving reliability and operating efficiency of electric power systems of commonwealth countries (using example of power plants of Russia and the Republic of Uzbekistan)
Authors: Vasilyev Yu.S. , Elistratov V.V. , Kudryasheva I.G. , Mukhammadiyev M.M. , Urishev B.U.
Published: December 2020

The possibilities of using shunting properties of HPP units, HAPS (Hydro-accumulating power system) for energy storage and redistribution, as well as Pump Station as a consumer of the regulator in night load dips to increase the reliability of the electric power system (EPS) in the conditions of the current increase in the share of non-nondestructive capacities in Russia and Uzbekistan and the implementation of programs for the development of renewable energy sources, primarily the construction of wind and solar power plants, were considered.
Probe of process of multiple-loop chains of parallel and consecutive joints
Authors: Shаymamоv B. , Rahmatov D. , Khоlмurоdоv M. , Mukhtorov A. , Rаkhmamоvа M.
Published: December 2020

The article describes the formation of low-frequency currents in ferromagnetic oscillatory circuits. As a result of parallel and serial connection of multi-loop ferroresonance circuits, the frequencies of harmonics of the second-order amplitude of soft excitation are considered. Each of the schemes in the article is analyzed, and taking into account the industrial use of frequency converters, it makes it possible for further research on the production of frequency converters.
Remote method of temperature measurement in the focus of high-temperature solar furnaces
Authors: Makhmudov Sirozhiddin , Sobirov Yuldash , Abdurakhmanov Abdujabbor
Published: December 2020

The paper presents a remote method for measuring heated bodies up to 3000 °C under a concentrated flow of radiant energy from the sun. The article discusses the issue of improving the accuracy of temperature measurement by refining the emissivity of materials during irradiation with a highly concentrated radiant flux.
Features of optimization of increasing the efficiency of an autonomous photo thermal installation for rural regions
Authors: Muminov R. , Tursunov M. , Yuldoshev I. , Sabirov H. , Kholov U. , Akhtamov T.
Published: December 2020

The paper considers experimental results on the development of a photovoltaic battery of a new design with increased efficiency and power with a new heat collector based on cellular polycarbonate, which leads to complete uniform thermal contact with the back surface of the photovoltaic battery. It is shown that the use of materials with a high reflection coefficient in the side plane of solar radiation reflection, increasing the accuracy of the operational guidance node to the sun using an upgraded support structure that allows orientation to the sun in two planes, reduces the loss of solar radiation energy. It is possible to control the capacity of the heat collector, which ensures the reliability of obtaining parameters, increases power, and ensures uniformity of the temperature of the rear surface of the PVB, which increases the efficiency of the installation.
Solution of optimization problems of high-inertial asynchronous electric drive
Authors: Tulyaganov Murot
Published: December 2020

The method of optimum start-up calculation on computer with use of the principle of a maximum and Newton-Rafson's method for the high-inertial asynchronous electric drive is offered. Based on this technique, optimal dynamic modes of high-inertia frequency-controlled asynchronous electric drive are calculated taking into account thermal processes. Methods of increasing electric motor energy efficiency due to reducing power consumption in dynamic modes are considered.
Graphical-analytical method for constructing load characteristics
Authors: Rasulov A N , Ruzinazarov M R , Muratov A S , Chariyeva M R
Published: December 2020

The article discusses a graphical-analytical method for constructing the load characteristics of a three-element resonant circuit in the current stabilization mode. The current stabilization mode is observed when compensating the negative section of the S-shaped characteristics of the parallel resonant circuit of the connected sequence with a linear inductance and with a linear capacitor characteristic. The equation of the load mode in a dimensionless form represents the equation of an ellipse, which makes it possible to construct the necessary characteristics of a three-element resonant circuit for various types of load.
Trends in development of architectural and planning solutions for Parish Church Complexes
Authors: Ivina Maria , Kondratieva Lydia
Published: December 2020

The article reveals the most important trends in the development of functional planning and spatial solutions of Christian parish Church complexes. The relevance of the topic is justified by the fact that modern tunneling complexes are not only places of religious practice, but also objects where educational, charitable, leisure and other activities of the parish can be carried out. Thus, a modern temple should be understood as a multifunctional complex, the design of which needs to develop special approaches. It is interesting to study the functional composition, planning structure, architectural and compositional solutions of parish complexes. Currently, the most widespread are multifunctional temple complexes of various directions, the figurative component of which is solved in the methods of innovative architecture. The task of designing them is extremely interesting and is solved in different ways by the professional architectural community.
The Analysis of Multi-Apartment Residential Buildings Energy Consumption in Russia
Authors: Lanko Aleksandr , José Sánchez de la Flor Francisco , Geraskin Yuri
Published: December 2020

The main reasons for the high energy consumption of residential multi-apartment buildings in Russia are the lack of motivation of developers in the construction and equipment of new buildings with a high energy efficiency class, as well as the insufficient number of energy metering devices. The main solution to the problem may be state support for energy-efficient technologies, compensation for excessive costs of the developer.
Response of the building with a stiffening core during an earthquake of February 02, 2018 in the territory of a metropolis
Authors: Lapin Vladimir , Yerzhanov Syrymgali , Kassenov Kamadiyar , Makish Nurakhmet , Essenberlina Dilfruza , Kassenov Dauren
Published: December 2020

Earthquakes give rise to a significant number of problems that affect environmental, seismic, and economic risks forthelocalsand construction sites. For the first time in the last 40 years, another local zero depth earthquake was registered in the territory of the city of Almaty. In terms of intensity, this was a 3-4-point earthquake. At 100 meters from the tectonic fault, there is a 16-storey building with a stiffening core and an engineering seismometric service station. With the use of AT 1105 sensors and a PCM-8 recorder, instrumental records of accelerations in the basement and on the roof of the building were recorded, and spectral β curves were constructed. The effective duration of the seismic impact in the basement of the building was quite significant, 47-56 seconds. There is undoubtedly an increase in the intensity of local earthquakes compared to 2007-2014. It was found that at the basement level the value of the vertical component is significantly less than the horizontal one. It is assumed that the abnormally high values of acceleration in the horizontal plane are a consequence of the presence of a tectonic fault near the building. Instrumental records of acceleration (accelerograms) can be used in calculations of both the seismic resistance of an object and the assessment of environmental, social, economic, and non-economic risks.
Influence of longitudinal force and internal pressure on the frequency of free vibrations of an underground oil pipeline
Authors: Dmitriev Andrey , Sokolov Vladimir , Bereznyov Aleksey
Published: December 2020

This paper is based on the equation obtained earlier by V.G. Sokolov to find the frequencies of natural vibrations of straight sections of large-diameter pipelines. In this work, to take into account the effect of hydrostatic pressure on the pipeline wall from oil flowing at different speeds, the solution obtained by M.A. Ilgamov and A.S. Volmyr is used. At the same time, the effect of a stationary fluid flow on the pipeline wall is taken into account in the equation written in forces for the last term of the normal component of inertia forces. The resulting modified equation allows determining the frequency characteristics of the pipeline both according to the rod theory (without taking into account the deformation of the cross section) and according to the theory of shells (taking into account the deformation of the cross section).
Analysis of the possibility of using polylactide in production of building materials
Authors: Kaddo Maria
Published: December 2020

The article analyzes the features of the production, use and utilization of biodegradable biopolymers. The results of studies are presented, the purpose of which is to assess the combination of properties of polylactide for use in construction. The fundamental possibility of using a thermoplastic biopolymer based on lactide (lactic acid) for the production of building materials is considered. Comparative data on the results of studies of the physical and mechanical properties of materials based on polylactide are presented.
Provision of the population of Saint Petersburg with green construction objects
Authors: Ershova Svetlana , Orlovskaya Tamara
Published: December 2020

The results of studies of greening areas of Saint Petersburg are presented. Differentiation was carried out by indicators of the area of public parks; the area of public green spaces per 1000 inhabitants; share of the area of public green spaces in the district. According to the ranking results, groups of districts have been identified, which make it possible to assess the relative level of greening of the territory of districts and the availability of large green public spaces for the population. Carrying out a study based on the proposed methodology makes it possible to consider the heterogeneity of the complex development of the city territory by various factors. Approbation of the methodology in the context of the administrative districts of Saint Petersburg made it possible to assess the quality of the urban environment by the level of provision of the population with green areas and to set priorities in the green building strategy. The results obtained can be used as a basis for the formation of standards for urban planning of Saint Petersburg, analytical material for adjusting the investment priorities in green building and the formation of programs for the integrated development of city territories.
Human wellbeing and automotive industry: correlations in the era of economical digitalization
Authors: Dudukalov Egor , Subhani Muhammad Imtiaz , Ushakov Denis
Published: December 2020

This research studies the relation between human wellbeing and automotive industry, as to whether the performance of automobile industry translates to an overall well-being of the populace. The study is based on secondary-data, and mainly takes into account the Prosperity-Index / ranking and its possible linkage with automotive sale volume of the nations. Findings of this study confirms that that the higher the prosperity index or ranking, the higher the automotive sales volume for most of the nations but several factor should be taken in to consideration, for example India automotive sale volume is bigger than the automotive sales volume of France but France prosperity rank is 19 and India in on 88 rank, it is because of the size and population of the country, India might have 10 times more population than France when divided among the population France may investing much more than India on their citizen. Findings reveal that Canada leads the table on first position with Australia on second position in the prosperity ranking, due to they provide enough opportunities for their people to live a good and healthy lives and these can be observed in terms of good automotive sales volume by these two nations. Further, finding also reveals that the automotive sales number of United States of America or several other countries have large value but that does not mean that they are also good in ranking in Prosperity Index which implies that the prosperity ranks has no direct relation with the automotive sales volume that a country generates.
Analysis of boundary conditions in design circuits influence on the shaft line operating state
Authors: Khalyavkin Alexei , Makeev Sergey , Salamekh Ali , Ivanovskaya Aleksandra
Published: December 2020

The work investigates the bearing piece boundary conditions influence on the shaft line operating state, with respect to elastic properties of stern-tube bearings. It is noted that the shaft line is a part of the ship’s power plant and it is a shaft system, located on the same axis. Performance criterion is the deflection of the concentrated load in the design scheme`s action point, modeling the propeller`s weight, bearing parts reactions and the natural frequency of linear lateral oscillations. The design scheme itself is a beam, resting on two elastic supports with a k stiffness factor, with concentrated load acting on the one end and three variants of the boundary conditions: pinched, hinged and sliding supports on another one. The results of calculations are given for different boundary conditions and the stiffness factors of elastic supports. The diagram of natural frequencies of linear lateral oscillations of ship`s shafting line is presented.
Transport industry as a business infrastructure: modern stage and prospects of development
Authors: Vanpetch Pakrawee , Ostovskaya Anastasia
Published: December 2020

The condition of the motor transport industry largely defines the progressive socio-economic changes in any country. It also serves a basic index of state development from the perspective of standards of living and healthy environment for economic growth and business activities. The motor transport industry reflects efficiency of the state policy, which also includes effective budget funding of the industry. The most developed countries make a considerable effort to maintain the motor transport system infrastructure and to stimulate development and integration of innovation technologies, which meets the goals of the national economy’s sustainable development. Paper analyzes some modern patterns and prospects of transport industry development on the examples of Asia and Russia economical systems.