-
Date submitted2024-04-11
-
Date accepted2024-11-07
-
Date published2025-01-17
Thyristor booster device for voltage fluctuation reduction in power supply systems of ore mining enterprises
The article is devoted to solving the problem of voltage fluctuations in the power supply systems of ore mining enterprises. The connection of high-power consumers with abruptly variable operating mode (for example, high-voltage mining excavators) causes voltage fluctuations and sags, disabling electrical equipment, communication, and automation devices in the 6-10 kV distribution network, which disrupts technological processes, etc. The use of existing solutions and methods to reduce voltage variations caused by dynamic loads is not effective. To solve the problem, booster transformers with high-speed thyristor switches can be used to work out switching the control steps towards increasing or decreasing the voltage. The authors offer a new circuitry solution for a thyristor booster device (TBD) with a pulse-phase control method. The purpose of the research is to determine the control laws of TBD, which enable to effectively reduce voltage fluctuations from dynamic load in the power supply systems of mining enterprises. The article provides a schematic diagram of the TBD and describes the principle of operation of the device. Some modes of increasing and decreasing the output voltage of the TBD, as well as the basic mode (without voltage addition) are provided. Mathematical modeling of TBD control processes was carried out and adjustment characteristics were set taking into account the load power factor. On a simulation computer model of a 6 kV electric network with a dynamic load, the verification of the adjustment characteristics of TBD obtained during mathematical modeling was carried out. Based on the research results, the laws for regulating the output voltage of TBD were established. The TBD effective control range with normal permissible limits of odd harmonics have been determined. The conducted research will make it possible to implement the device control system.
-
Date submitted2023-11-15
-
Date accepted2024-09-24
-
Date published2024-12-25
Development and validation of an approach to the environmental and economic assessment of decarbonization projects in the oil and gas sector
- Authors:
- Nadezhda A. Sheveleva
This article addresses the problem of selecting a priority decarbonization project for an oil and gas company aiming to reduce greenhouse gas emissions. The wide range of decarbonization options and assessment methods prompted the development of a comprehensive ranking system for project selection. This system incorporates both internal and external factors of project implementation, a two-stage algorithm that filters out unsuitable projects taking into account sustainable development goals, and a quantitative evaluation approach using absolute and relative indicators. The proposed system evaluates decarbonization projects by considering not only the reduction of emissions in both absolute and relative terms, but also the broader environmental, social, and economic aspects relevant to the oil and gas company and the national economy. It includes a ranking mechanism for identifying priority projects and integrates carbon regulation incentives and green taxonomy tools into the economic assessment for more precise comparative analysis. The quantitative assessment in absolute terms involves a specialized net present value calculation, which accounts for revenue from both carbon credit sales and the potential sale of new low-carbon products, if applicable. The proposed assessment provides for targeted analysis of specific performance indicators, such as the cost per unit of emissions reduced, tax and social security contributions per unit of emissions reduced, energy efficiency improvements, and other indicators used for additional assessments of projects under otherwise equal conditions.
-
Date submitted2023-07-07
-
Date accepted2023-12-27
-
Date published2024-08-26
Landslide hazard assessment in Tinh Tuc town, Cao Bang province, Vietnam using Frequency ratio method and the combined Fractal-frequency ratio method
Landslides are one of the most frequent natural disasters that cause significant damage to property in Vietnam, which is characterized by mountainous terrain covering three-quarters of the territory. In 17 northern mountainous provinces of the country, over 500 communes are at a high to very high landslide hazard. The main goal of this study was to establish landslide hazard maps and conduct a comparative evaluation of the efficiency of the methods employed in Tinh Tuc town, Cao Bang province. The landslide hazard assessment was carried out in this study using the combined Fractal-frequency ratio (FFR) and the Frequency ratio (FR) methods. The FR method is based on the actualist principle, which assumes that future landslides may be caused by the same factors that contributed to slope failure in the past and present. The FFR method is based on the determination of the fractal dimension, which serves as a measure of the landslide filling density in the study area. Eight landslide-related factors were considered and presented in cartographic format: elevation, distance to roads, slope, geology, distance to faults, land use, slope aspect, and distance to drainage. Determining the area under the receiver operating characteristic curve (ROC-AUC) and verification index (LRclass) was performed to assess the performance of prediction models and the accuracy of the obtained maps. As a result, five zones were identified for the study area, characterized by very low, low, moderate, high, and very high landslide hazards. The analysis of the reliability of the obtained landslide hazard maps using the AUC and LRclass indices revealed that the FFR model has a higher degree of reliability (AUC = 86 %, LRclass = 86 %) compared to the FR model (AUC = 72 %, LRclass = 73 %); therefore, its use is more effective.
-
Date submitted2021-11-10
-
Date accepted2022-05-25
-
Date published2022-12-29
Predicting the permeability of the near-bottomhole zone during wave impact
The research reveals that during selection of a method to increase oil recovery it is necessary to take into account rheological features of fluid movement through the formation, effect of capillary forces and heterogeneity of reservoir properties of the productive formation in thickness and along the bedding. Low-frequency wave impact, which is used to increase production in oil fields, is considered. At low-frequency impact new fractures appear and existing fractures in rocks increase in size. The greatest increase in porosity and permeability of rocks occurs at an impact frequency up to 10 Hz. Dynamics of oscillation amplitude during wave's movement in saturated porous medium is studied in the paper: essential attenuation of amplitude occurs at distance up to 1 m from borehole axis. With increase of frequency from 1 to 10 Hz the intensity of amplitude's attenuation decreases. The technology was tested on a well in Perm region (Russia). The actual permeability value was 50 % higher than the predicted value. According to the results of hydrodynamic investigations processing, it was noted that the greatest increase of permeability took place near the wellbore, while away from the wellbore axis permeability remained almost unchanged. In order to refine the mathematical model for prediction of wave impact on rock permeability it is necessary to take into account interconnection of pore space structure, change of adhesion layer, as well as to study transfer of particles during vibration.
-
Date submitted2021-06-08
-
Date accepted2021-11-30
-
Date published2021-12-27
Management of groundwater resources in transboundary territories (on the example of the Russian Federation and the Republic of Estonia)
Groundwater, as a source of water supply, the most important mineral and geopolitical resource, , is often the only source of high-quality drinking water that is protected from pollution under conditions of increasing deterioration of surface water quality. Transboundary groundwaters are the focus of hydrogeological researchers for a number of reasons, including the reduction and pollution of water resources as a result of economic activities. The increased controversy between states over transboundary water issues has necessitated the development of international legal documents on issues related to water conflict prevention and the sustainable use of fresh water. As part of the analysis of the problem of legal regulation of groundwater extraction from transboundary aquifers and complexes, it is proposed to consider this aspect on the example of Russia. The problems of regulation of rational use and protection of fresh water in the bilateral treaties of the Russian Federation were revealed; a methodology for the management of groundwater extraction in the territory of the transboundary aquifer was developed, the size, parameters, and factors influencing the formation of the transboundary zone have been determined (based on research and analysis of water intake activities in the border areas of the Russian Federation and the Republic of Estonia) were determined.
-
Date submitted2021-02-05
-
Date accepted2021-03-30
-
Date published2021-04-26
Assessment of negative infrastructural externalities when determining the land value
- Authors:
- Elena N. Bykova
The work forms and substantiates the concept of land value, based on a new institutional theory. The infrastructural component of the cost of land in the presented concept determines, on the one hand, the efficiency of the use of natural resources, properties, demand for land on the market, on the other hand, the costs, which are determined not only by capital investments in construction of engineering infrastructure, but also by losses associated with restrictions on activities within zones with special conditions for territory use, creation of unfavorable conditions for economic activity, small contours, irregularities and others on a specific land plot, which are external negative infrastructural externalities that create losses of rights holders of land plots that are not compensated by the market, falling within the boundaries of these zones. Methods for assessing the impact of such negative infrastructural externalities on the cost of land encumbered by zones in different conditions of land market activity have been developed and tested, based on an expert-analytical approach (depressed market); the ratio of market values of land plots encumbered and unencumbered by a specific zone, and qualimetric modeling (inactive market); modeling by introducing into the model the factor of presence of zones with special conditions for territory use, based on the grouping of zones according to similar regulations for use, or by introducing the parameters of this factor (active market). Methods for taking into account spatial deficiencies and compensating for restrictions and prohibitions on activities on the territory of land plots with an individual market assessment are proposed.
-
Date submitted2019-03-31
-
Date accepted2019-08-25
-
Date published2020-02-25
Cascade frequency converters control features
The structures of systems with high-voltage cascade frequency converters containing multi-winding transformers and low-voltage low-power converters connected in series at each output phase of the load are considered. Low-voltage blocks contain three-phase diode or active rectifiers, DC capacitor filters, single-phase stand-alone voltage inverters and block disconnecting devices in partial modes (in case of failure when part of the blocks are disconnected). The possibilities of operation of cascade converters are determined, equations for correcting tasks to units in partial modes are given, tables of correction of tasks with estimates of achievable load characteristics are proposed. The results of experiments on the model of a powerful installation with a cascade frequency converter are presented, confirming the possibility of ensuring the symmetry of the load currents when disconnecting part of the blocks and the asymmetry of the circuit.
-
Date submitted2019-05-05
-
Date accepted2019-07-03
-
Date published2019-10-23
Scraper Face Conveyors Dynamic Load Control
- Authors:
- E. K. Eshchin
The task of controlling the dynamic loading of scraper face conveyors (SC) is considered and the unsatisfactory state of loading of mechanical and electrical components of the SC is recorded. The possibility of the appearance of a self-oscillatory nature of the entire system load due to the peculiarities of the movement of the traction chain along the lattice frame of the SC is indicated. The property of the system is noted – the cyclic nature of the loading of the circuit during movement, which causes energy exchange processes between the mechanical and electromotive components of the conveyor (when using the head and tail electric drives) through the common cable network of the power supply system of the SC. A high level of dynamic loading of the electromechanical system causes the problem of eliminating the self-oscillating operating mode of the SC that generates it which is proposed to be solved by changing the angular rotation speeds of the SC drive sprockets. Angular speeds can be changed by applying frequency control of asynchronous electric motors. The efficiency of setting the frequency of electric motor stator currents of the head and tail drives of the conveyor is established in proportion to the frequency of rotors rotation to eliminate self- oscillating modes of operation in the main operating mode. The possibility of reducing the starting shock values of the electromagnetic moments of electric motors is considered. The results of the calculation of the start-up and liquidation of the self-oscillating operating mode are presented on the example of the scraper face conveyor Anzhera-34. The results of calculations of the start-up modes and the main operational transportation of coal in an uncontrolled mode of operation and after the introduction of control are compared, based on which it is concluded that it is advisable to use active control of the dynamic loading ofSC.
-
Date submitted2019-03-13
-
Date accepted2019-05-18
-
Date published2019-08-23
Improving the Operation of Pump-ejector Systems at Varying Flow Rates of Associated Petroleum Gas
- Authors:
- A. N. Drozdov
- Ya. A. Gorbyleva
Application of pump-ejector systems for the utilization of associated petroleum gas reduces the negative environmental impact of its flaring, and also allows the implementation of a promising method of water-gas stimulation of the formation, which effectively increases oil recovery. Equally feasible is the use of pump-ejector systems in the operation of oil wells with a high gas factor, low bottomhole pressures to increase production rates and increase the turnaround period. A significant change in the flow rate of associated petroleum gas over time is a serious problem for the efficient operation of pump-ejector systems for the utilization of associated petroleum gas. To ensure the rational operation of the pump-ejector system under the condition of a variable flow rate of associated petroleum gas, experimental studies of a liquid-gas ejector characteristics were carried out. The article presents the results of the research, obtained pressure-energy characteristics of the investigated jet apparatus at various values of the working stream pressure before the ejector nozzle. The possibility of adapting the operation of pump-ejector systems to changes in the flow rate of the pumped gas, regulated by the working pressure and fluid flow rate through the nozzle is revealed. To successfully change the operation of the pump-ejector system, the possibility of frequency regulation of the pump shaft's rotation at changing gas flow rates in a small range of values is considered. With a large difference in the values of the possible flow rate of associated petroleum gas, it is recommended that frequency regulation should be supplemented by periodic short-term operation. The possibility of increasing the efficiency of the pump-ejector system when using salt solutions with a concentration that contributes to the suppression of bubble coalescence is noted.
-
Date submitted2018-07-19
-
Date accepted2018-09-21
-
Date published2018-12-21
Administrative methods of import substitution management of deficient types of mineral raw materials
- Authors:
- V. Yu. Khatkov
- G. Yu. Boyarko
Import dependence of Russian consumers on certain types of mineral products: aluminum, manganese and chrome raw materials, titanium, zircon and tin concentrates, ferroniobium, fluorspar and others – increases the stability of many industries. The state regulation of import substitution is very effective, but only in the form of indirect (coordination, maintenance, promotion, supervision and control), and not direct methods. The following are used as tools for the administrative management of import substitution: the establishment of legal norms for the implementation of import substitution actions; coordination of actions of authorities and industry on import substitution; state control of railway transportation rates; limited government control over the pricing of import-dependent mineral products and services associated with them; financing of import substitution projects. In order to reduce import dependence, the following is proposed: to lower the charges for railway transportation of import-dependent mineral products sent for the needs of Russian consumers, primarily for oncoming import-export goods (boric acid, borax, tungsten ores); to manage the pricing of export-oriented mineral products through a system of import and export customs duties, which prevent the excessive export of scarce mineral raw materials in demand within the Customs Union and stimulate its sales in the domestic market.
-
Date submitted2017-09-03
-
Date accepted2017-11-04
-
Date published2018-02-22
Development of sensorless vector control system for permanent magnet synchronous motor in Matlab Simulink
- Authors:
- V. Ya. Frolov
- R. I. Zhiligotov
In last 20 years segment of electric drives with permanent magnet synchronous motors has increased. This type of motors has better technical characteristics compared to induction motors, but has problems in actual implementation, one of which is the requirement of rotor position data. It is possible to implement with use of sensors or without them by means of motor state observer. The paper describes problems of sensorless vector control system for permanent magnet synchronous motors. The vector control system with state observer for permanent magnet synchronous motors is described. Synthesis of sliding mode observer for rotor speed and position is presented. The algorithm is implemented by development of model in Matlab Simulink environment with support by Texas Instruments processors support blocks. Experimental comparison of results of rotor angle state calculation and the data obtained by rotor position sensors was conducted. Research objective is a development of control algorithm, which has required precision for calculation of rotor start angle, high range of speed regulation and resistance to drift of motor parameters.
-
Date submitted2016-11-16
-
Date accepted2017-01-01
-
Date published2017-04-14
Complex use of heat-exchange tunnels
- Authors:
- A. F. Galkin
The paper presents separate results of complex research (experimental and theoretical) on the application of heat-exchange tunnels – in frozen rocks, among other things – as underground constructions serving two purposes. It is proposed to use heat-exchange tunnels as a separate multi-functional module, which under normal conditions will be used to set standards of heat regime parameters in the mines, and in emergency situations, natural or man-made, will serve as a protective structure to shelter mine workers. Heat-exchange modules can be made from mined-out or specially constructed tunnels. Economic analysis shows that the use of such multi-functional modules does not increase operation and maintenance costs, but enhances safety of mining operations and reliability in case of emergency situations. There are numerous theoretic and experimental investigations in the field of complex use of mining tunnels, which allows to develop regulatory design documents on their basis. Experience of practical application of heat-exchange tunnels has been assessed from the position of regulating heat regime in the mines.
-
Date submitted2015-08-18
-
Date accepted2015-10-06
-
Date published2016-04-22
Energy- efficient control of asynchronous motor drive with current refinement of the loss minimum on the basis of fuzzy logic
- Authors:
- O. B. Shonin
- V. S. Pronko
Currently, asynchronous electric drive on the basis of semiconductor frequency converters is widespread because of the relative simplicity and reliability of the design, the use of digital control systems, providing the accuracy and flexibility of process control, which allows for a significant increase in product quality, reduction in energy consumption and improvement of the enterprise profitability. In spite of these advantages, the problem of ensuring high energy efficiency of the drive in wide range of its operational modes is still not solved in full scale. The paper is devoted to the reduction of losses in the asynchronous drive on the basis of en-ergy-saving control algorithms that aim to ensure the desired mode of the driven mechanism while minimizing losses in copper and steel of the motor. On the basis of the motor model, taking into account magnetic losses, dependences of losses in the copper and steel, as well as the total loss from the absolute slip have been derived for different operating points of the drive. The optimal values of the absolute slip for different speeds of the rotor have been obtained for use in the con-trollers ensuring operation of the drive at maximum efficiency, highest power factor and minimum of the stator current. For minimizing the losses in the drive when changing the motor parameters it has been offered the combined method based on the method of loss model and iterative method of searching the minimum of power consumption. The effectiveness of the proposed control system using fuzzy logic is confirmed by comparing the graphs of losses and efficiency, obtained at using a traditional control law and the optimal control law.
-
Date submitted2014-12-27
-
Date accepted2015-03-01
-
Date published2015-12-25
Minimization of energy losse when starting a variable frequency drive through application of a genetic algorithm of optimization
- Authors:
- O. B. Shonin
- V. S. Pronko
In the face of energy lack and rising energy prices one of the priorities of current researches is to improve energy efficiency of electric drives, which are widely used in modern industrial plants. Existing methods of minimizing losses are mainly designed for stationary regimes. At the same time, the development of algorithms for reducing losses in transient and in particular starting conditions is given little attention. Due to the high complexity of the description of the multivari-ate dynamic processes determining the optimal control laws is advantageously to be carried out us-ing stochastic optimization methods. The work seeks to substantiate the optimal starting character-istics of an asynchronous drive based on a genetic algorithm. A feature of the proposed method of optimization is the use of multiple simulation experiments to find start-up characteristics which provide a minimum energy loss. Automation of the search is performed using the developed pro-gram, which includes a module of a genetic algorithm and a module for interfacing with the elec-tric model in the MATLAB/Simulink environment. The program allows choosing the parameters of the genetic algorithm along with controlling the process of optimization. Application of the proposed method allowed obtaining the optimal starting characteristics «voltage – frequency» in a tabular form with consequent linear approximation of the data. Increase in efficiency due to the proposed start up law has been confirmed by comparing the simulation re-sults under conditions of using a traditional linear characteristic and derived optimal law. The es-timation of losses reduction has been carried out at the drive load of different kind in a wide range of its variation.
-
Date submitted2014-11-18
-
Date accepted2015-01-04
-
Date published2015-10-26
A new stage in the development of the european natural gas market as a reflection of transition to national state capitalizm
- Authors:
- N. G. Privalov
- T. B. Li
This article is devoted to the analysis of a situation and tendencies of development in the European natural gas market. The evolution of «energetic doctrine» models – from domination of great state monopolies to a competitive energetic doctrine – has been happening for the last 60 years. «The new global energetic doctrine» which includes state and interstate regulation strengthening is being formed now. An aggravation of contradictions in the natural gas market is a manifestation of a new stage in the mixed economy formation – the national state capitalism.
-
Date submitted2014-06-23
-
Date accepted2014-09-15
-
Date published2014-12-22
Topical issues of the management of extraction of underground waters on the territory of the Russian Federation
- Authors:
- N. V. Pashkevich
- E. I. Golovina
Water is a key component of our environment; it is a renewable, limited and vulnerable natural resource, which provides for the economic, social, and environmental well-being of the population. The modern system of taxation and regulation of subsoil use in the extraction of groundwater is currently imperfect and has definite disadvantages, among them not enough control of natural resources by the state, the commercialization stage of licensing, and the budget deficit, which is passed on to other areas of the national economy. General information about the state of the underground water supply in Russia, and the negative trends of underground water use are presented. The system of licensing underground water intakes in Germany is briefly described; some measures to improve the system of man-agement of Russia’s underground waters fund are suggested.
-
Date submitted2010-07-15
-
Date accepted2010-09-13
-
Date published2011-03-21
Experimental setup for research Influence of vibromechanical treatment on mechanical properties of welded joints
- Authors:
- O. F. Khafizova
- V. I. Bolobov
The description of developed experimental setup for welding product that made of pipeline steels with application of applying vibration with intended frequency approximating to natural-vibration frequency of welded construction unit of pipelines during the welding cycle is presented.
-
Date submitted2010-07-06
-
Date accepted2010-09-14
-
Date published2011-03-21
Electromechanical processes in electric drives of mountain equipment on the basis of the synchronous electric motor
- Authors:
- A. O. Sviridenko
The description is given and the function chart of the bench installation is resulted, allowing to reproduce static and dynamic modes of adjustable electric drives of an alternating current. The modes considered during experimental researches of the electric drive on the basis of the synchronous electric motor, working in a mode of ventilniy electric motor are listed. Conclusions are drawn on character of course of dynamic modes, comparison of the electric drive to the synchronous electric motor and the electric drive of a direct current with the subordinated regulation is given.
-
Date submitted2010-07-20
-
Date accepted2010-09-14
-
Date published2011-03-21
The physical breadboard model of dynamically counterbalanced drilling string with swinging movement with the asynchronous electric drive powered by inverter laboratory experimental researche
- Authors:
- V. V. Ivanik
The laboratory experimental stand for research of the asynchronous resonant electric drive on a physical breadboard model of dynamically counterbalanced drilling string is developed. The asynchronous electric drive with swinging movement the autoresonant oscillation mode is realized.
-
Date submitted2010-07-08
-
Date accepted2010-09-02
-
Date published2011-03-21
The autoresonant asynchronous electric drive of dynamically counterbalanced drilling string on carrying cable with swinging movement fluctuations amplitude stabilization
- Authors:
- E. A. Zagrivnyi
- V. V. Ivanik
The algorithm of resonant fluctuations amplitude stabilization of dynamically counterbalanced drilling string on carrying cable with swinging movement of jackbit is developed. Imitating modeling of the resonant asynchronous electric drive with swinging movement of jackbit with the frequency converter in various operating modes is resulted.
-
Date submitted2010-07-26
-
Date accepted2010-09-14
-
Date published2011-03-21
Algorithm of control of the electric drive with ventilniy electric motor and the converter of frequency with the active rectifier
- Authors:
- A. P. Emelyanov
- A. O. Sviridenko
Advantages of application of the active rectifier as a part of converters of frequency for powerful drives with ventilniy electric motors are considered. The mathematical description of the processes proceeding in a power part of the active rectifier is given. The scheme of a drive with a vector control system with the gage of position of a rotor and the active rectifier is presented, schedules of power consumption and a current by a drive with the active rectifier are resulted.
-
Date submitted2009-09-26
-
Date accepted2009-11-14
-
Date published2010-06-25
Automatic bulk solids moisture in stream control system
- Authors:
- S. S. Galushkin
- B. A. Vishniak
- V. N. Smirnov
Automatic moisture in fine-dyspersated stream control system based on microwave frequency method is presented. Minimizing means of interrupting factors peculiar to this method of measurement are produced and systematically proved.
-
Date submitted2009-08-17
-
Date accepted2009-10-25
-
Date published2010-02-01
Compensation of supply station reactive power by means of the mine main fan electric drive
- Authors:
- V. V. Sobolev
- O. B. Shonin
On the basis of comparative analysis of the mine main fan electric drive input voltage-current characteristics, a frequency-variable drive with pulse width modulation (PWM) rectifier and PWM inverter is shown to be the most competitive one because of its capability to independently implement the substation power factor correction and the mine air flow energy-saving control.
-
Date submitted2008-11-19
-
Date accepted2009-01-09
-
Date published2009-12-11
Improvement of Russian coal industry development strategy
- Authors:
- A. N. Martemyanova
The work is dedicated to the problems of Russian energy safety by means of perfecting and optimization of the developing strategy of coal industry. The condition of Russian coal industry was analyzed and the main factors, that have an influence on it, were determined. The vision and the main aims of the developing strategy of coal industry and the recommendations of the coal industry state regulation mechanism perfection for the long period were defined in the article.
-
Date submitted2008-11-19
-
Date accepted2009-01-23
-
Date published2009-12-11
The legal and economic conditions of attraction investments to the exploration in Russia
- Authors:
- A. A. Fedchenko
- V. G. Beliakov
The problems of rational use of the huge mineral-resource potential of Russia are considered. The causes of insufficient exploration volumes in Russia are analyzed. It is proposed measures of the legal regulations in order to create junior geological companies in Russia and increase private investments to the exploration of deposits.