The PURPOSE of the paper is to develop a methodology for calculating the main parameters (power and energy capacity) of an energy storage device based on the analysis of experimental load diagrams and taking into account its purpose as well as to illustrate methodology efficiency on specific practical examples. METHODS. The study uses the methods of mathematical modeling (using MATLAB/Simulink) and a passive full-scale experiment in the power system (for obtaining load diagrams). The Fourier method is used to perform the frequency analysis of the experimental load diagrams. RESULTS AND THEIR DISCUSSION. The paper proposes an algorithm and a procedure based on the harmonic analysis of the load diagram in order to select the main parameters of the energy storage device. The purpose of the storage device determines its application strategy. The article deals with two examples of energy storage device use. Based on the analysis of the results of the full-scale experiments the amplitude frequency response characteristics of load diagrams have been determined for each case and storage device parameters have been selected according to the developed procedure. CONCLUSIONS. The methodology proposed in the article allows to identify extraneous frequencies of load power oscillations based on the analysis of the experimental load diagram and select the energy storage device parameters for their suppression. Any power deviations from the given value, frequency range or individual frequencies can be extraneous. The energy storage device chosen by the method described in the article has sufficient power and energy capacity to achieve the set goal.

PURPOSE. There is the need for expansion of the influence zone of the electric power system of the Republic of Sakha (Yakutia) in order to ensure the reliability and economy of power supply with the maximum use of the advantages of centralized power supply. For this purpose along with the large-scale integration of solar and wind power stations it is necessary to implement the tasks of electric energy transportation as applied to the North-East of Russia on the basis of flexible power transmission systems using a thyristor voltage regulator. METHODS. Long-distance transportation of AC electric power can be performed by compensated or half-wave (tuned to a half-wave) power transmission. RESULTS. Half-wave transmission should be opted for when transmitting AC electric power to long- and super-long distances, since under the condition of stability it does not require additional costs for reactive power compensation while featuring an increased capacity. However, the advisability of tuning to a half-wave occurs when the line length is 1500 km or more. The line, which is shorter than 1500 km should be reduced to the line of «zero length». The reactance of the line whose length is shorter than the boundary length of 1500km is proposed to compensate and reduce to the “zero length” line in order to increase capacity and stabilize the voltage regime along the line using the thyristor stabilizer of parameters developed by the Larionov Institute of the Physical and Technical Problems of the North. CONCLUSION. Future electric power system must be flexible, reliable, cost-effective and environmentally friendly. This combination of tasks can be solved with the help of intelligent technologies. In this context the significance of Flexible Alternative Current Transmission System (FACTS) will increase more and more with the development of electric power systems.

The PURPOSE of the paper is development of methods and tools for adequate modeling of electrical power supply systems equipped with three-phase and single-phase transformers. METHODS. The methods of electrical power system (EPS) simulation in phase coordinates based on the models of elements in the form of lattice equivalent circuits with fully-meshed topology are used for mode determination of electrical power supply systems equipped with three-phase and single-phase transformers. The models and methods are implemented in the program complex Fazonord. RESULTS. The models of three-phase and single-phase converters by Steinmetz, Terekhin and Sinev circuits are provided in the article. It is shown that Steinmetz converters have the potential of balancing both two-phase and single-phase load. This allows simultaneous compensation of reactive power and complete use of three-phase transformer resources in case of such load connection. Terekhin’s curcuit is a standard capacitor scheme used for supplying low-power three-phase motors from a single-phase network. This circuit creates significantly asymmetrical system of three-phase voltages as a result acceptable asymmetry levels can be obtained only under certain conditions. Sinev's circuit provides good balancing adjustment, but the levels of voltages strongly depend on load currents. CONCLUSION. EPS mode determination introduced by Irkutsk state transport university allows to simulate electrical power supply systems equipped with three-phase and single-phase converters.

Modern gas-turbine and gas reciprocating generating units (GU) have a number of features having a significant effect on the flow rate and parameters of transient processes under various external disturbances to be taken into account when simulating electric regimes and choosing emergency control tools. The PURPOSE of the work is identification of the application features of gas turbine and gas reciprocating generating units in power consumption centres as well as determination of adequate and efficient emergency response measures. METHODS. The study is given to the parameters of electrical regimes. The complex of calculations of steady-state regimes and electromechanical transients in specialized software systems is conducted. RESULTS. The results of the analysis of a number of significant negative properties of gas turbine and gas reciprocating generating units of small and medium power used at the facilities of own generation are presented. The recommendations are given for their consideration when designing power supply systems and selecting emergency control tools. CONCLUSIONS. The simulation of electrical regimes, when performing technological connection of own generation facilities, should take into account the design features of modern gas turbine and gas reciprocating generating units in order to obtain adequate calculation results and to make correct technical decisions on equipping the generating plants and the adjacent network with emergency control facilities.

PURPOSE. The paper presents an algorithm and an implementing it computer program. The computer program is based on MS Excel and is designed to model nonlinear loads by measured variables to analyze non-sinusouidal modes and control power quality in electric networks. METHODS. As measured mode parameters represent time series of random discrete values the mathematical-statistical methods are used to develop the models of nonlinear loads. RESULTS AND THEIR DISCUSSION. The model of nonlinear load is represented by the set of values of active and reactive harmonic currents. These values can be defined through the identification of the distribution functions of the series of random values of harmonic currents and determination of their values with the probability of 0.95. СONCLUSIONS. The developed algorithm and computer program allow to model the harmonic currents of nonlinear loads by the measured parameters of the network mode. The latter is represented by a series of random values that have not only the distribution functions described in special literature but also their combinations.

PURPOSE. Increased renewable generation requires new operation strategies of power systems especially at distribution levels. New mechanisms - so-called flexibility options - are necessary for smoothing the weather dependence of renewable generation and stabilizing the Smart Grid operation in this way. The paper presents different flexibility options of a Smart Grid. Moreover, some practical examples of modern Smart Grid operation have been given and the methodology for flexibility option planning has been presented. A wide range of modern references and summary make this review paper useful as an introduction to this future-oriented scientific topic. METHODS. Operation of power system with renewable sources often causes bottlenecks in the power grid. The used method is redispatshing the power generation or application of local flexibility options e.g. energy storages or demand management. RESULTS AND THEIR DISCUSSION. The electric power system of the future, which will use renewable generation, needs a flexibility option for stabile and economically profitable operation. The list of such flexibility options and the selection methodology of optimal flexibilities mix is presented in this paper. The optimal selection depends on the power system structure and current operation condition as well as can change rapidly. CONCLUSIONS. The strategies of power system operation are to be checked in some countries due to the wide presence of the large proportion of renewable and other decentralized generation. In the future the percentage of renewable generation will increase even faster therefore today there is the need to develop a wide range of flexibility options to stabilize and optimize the power system operation. Having overviewed the possible measures, this paper shows how to transfer them in general into the planning and operational practice. The paper provides both general remarks and real examples. The future works will focus on the development of algorithms for optimal flexibility and practical operation of Smart Grids.

The PURPOSE of this article is to improve the efficiency of using electrical energy and cost saving related to infrared heating systems in buildings. MATERIALS AND METHODS. The concrete floor in Irkutsk National Research Technical University classrooms where the experiment has been held is covered with laminate with installed thermocouples. The study is given to a patented heating device. The TRM138 device by OWEN company registers the signals from the thermocouples using the standard software supplied together with the Owen Process Manager devices. Resulting graphs of temperature field distribution are imported in MS Excel software. IMS-F1.SHCH1 device of OWEN company controlles the voltage of the consumed current and power. RESEARCH RESULTS. The study has been given to the temperature modes provided by infrared heaters depending on the applied thermoregulation devices. The factors influencing the effective operation of infrared heating systems are presented. The effect of control systems on efficient operation is demonstrated. A detailed analysis is given to the range spread of temperature fields depending on the effect of inner and/or outer factors. CONCLUSIONS. It has been determined that heating devices that use the patented heating element with a distributed heating layer stabilize the scatter of temperature indices of the heated surface. It also has been concluded on the need for considering the value of the convection and radiant heating component ratio taking into account the characteristics of the building and the ways of its operation when designing heating systems.

The PURPOSE of the article is to improve the machining efficiency of parts made of high-strength materials through the application of specialized and purpose-designed mills with alternative cutting patterns. METHODS. The study uses experimental and theoretical methods examining the improvement of the performance of specialized and purpose-designed mills with alternative cutting patterns under the rough milling of high-strength materials. RESULTS AND THEIR DISCUSSION. The application efficiency of alternative cutting patterns in the specialized and purpose-designed mills has been studied under the rough milling of high-strength materials. CONCLUSIONS. Application of alternative cutting patterns in the specialized and purpose-designed mills significantly reduces (by 1.5-3 times) the loads on the technological system, provides the formation of fine transportable chips. The latter enables to increase the number of mill teeth and intensify milling modes by not less than 50-150% with simultaneous improvement of durability.

The PURPOSE of the paper is to determine the influence patterns of machining parameters of polymeric face abrasive brushes on cutting forces at finishing processing of part planes. METHODS. The study was conducted by mathematical modeling of brush filament interaction with the processed edge and experimental confirmation of calculation results on the face brushes of various granularity of Scotch-Brite™ BD-ZB brands of 3M company. RESULTS AND THEIR DISCUSSION. The article considers the interaction process of face brush filaments and the processed edge. Cutting forces ( Р_X, Р_Y, Р_Z ) are formed by means of elastic and shock components. Influence patterns of rotation frequency, deformation, feed and edge offset of the brush axis on all the components of the cutting forces are determined. Using mathematical dependences all forces are calculated from the listed processing parameters and presented in the form of tables and graphs. Determination of forces on a three-component dynamometer of 9257B model of Kistler company (Switzerland) has shown good coincidence of theoretical and experimental data. Moreover, the results received experimentally are presented in the form of mathematical dependences. CONCLUSION. Polymeric face abrasive brushes are very effective at finishing processing of the planes of parts made of various materials. Based on the knowledge of mechanical properties of polymeric abrasive material and the size of brush filaments it is possible to determine all the components of the cutting force by the developed mathematical model. When developing technological processes it allows to make a reasonable choice of equipment to perform the finishing operation or make recommendations on the design of special equipment.

The article deals with the possibility of evaluating dynamic states in the interaction between the elements of electric locomotive traction motors and devices providing switching processes. The PURPOSE of the study is to develop a mathematical modeling method for assessing the features of dynamic states arising under the increased level of vibration. METHODS. The paper proposes a mathematical model of commutator-brush assembly operation of the traction motor as a composite solid, in which the conditions of contact non-breaking can be implemented under the joint vibrations of the composite solid elements and influence of harmonic forces. A methodological basis is developed for the assessment of dynamic states of the interaction of commutator-brush assembly elements under the traction motor body vibrations arising under the interaction with the rail. The methods of structural mathematical modeling, in which the mechanical oscillatory system is correlated to a structural model that is dynamically equivalent of the automatic control system, are used to build the mathematical models. RESULTS AND THEIR DISCUSSION. The possibilities to estimate the effect of external vibrations of the traction motor body on the operation of the commutator-brush assembly are shown taking into account the possibilities of oscillations of the traction electric motor armature. Description is given to the sequence of actions on reduction of the problem of complex loading at the simultaneous action of several forces to the simplified setting of the problem of estimation of element contact loading conditions at switching. CONCLUSIONS. The method is proposed to construct a mathematical model of commutator-brush assembly elements contact under traction motor body vibration. The article provides a mathematical model of commutator-brush assembly operation under traction motor body vibration which is represented by the design scheme in the form of a mechanical oscillating system with three degrees of freedom.

The PURPOSE of the paper is determination of the efficiency of dust cleaning by a wet scrubber as the third gas purification stage of “RUSAL Achinsk” JSC sintering furnaces with the use of a sub-slurry water (SSW) as a gas-cleaning solution and setting of optimal operation conditions for the equipment. METHODS. Pilot-industrial tests have been carried out on two wet gas-cleaning installations of centrifugal-vortex type with the capacity of 200 thous. m³/h. The installation includes two scrubbers having dispersing lattices with guide blades, two droplet separators and a system of gas-cleaning solution feeding and subsequent collection of the spent solution in the scrubber bottom. Two scrubbers connected in parallel represent the third gas cleaning stage of the sintering furnace. RESULTS. When the consumption of the sub-slurry water is 0.3-0.45 dm³/Nm³ of the cleaned gas the efficiency of dust removal is 85% on average (under the gas consumption of 350,000 m³/h) and reaches 96% (under the gas consumption of 200,000 m³/h). It has been determined that sharp increase in water consumption - above 1.0 dm³/Nm³ of the cleaned gas - causes sharp fall of the dust removal efficiency (up to 40%). This is the result of the formation of a continuous water curtain in the system which prevents the formation of a centrifugal gas movement. The content of gases emitted to the atmosphere (CO, NO, NO₂, SO₂) obtained at the outlet of scrubbers is significantly lower than the values set by the maximum permissible emission (MPE). СONCLUSION. The use of sub-slurry water as a gas-cleaning solution on the third “wet” stage of gas cleaning organized to extend the already existing at the enterprise system “dust chamber - electrostatic precipitator” will allow to give up the organization of an expensive department of preparation and regeneration of the gas cleaning solution and to carry out the repulping of trapped technological dust in gas cleaning equipment followed by pulp feeding in wet nepheline charge for sintering. The efficiency of scrubber gas cleaning reaches 96% at the designed capacity and at the increased productivity up to 350 thous. m³/h constitutes an average of 85%.

PURPOSE. The hydrometallurgical processing of roasted copper concentrate leach solutions by sorption with the following electrolytic precipitation of copper is studied. METHODS. Sorption of copper and silver is proposed from the obtained sulphate solution on an ionite Lewatit MonoPlus ТР-220. RESULTS AND THEIR DISCUSSION. The sorption process features high technological parameters and its concentrations don’t reach a breakthrough. Copper ion exchange capacity is 56g per liter of resin; silver sorption is at the fullest extent possible. Copper is stripped by the solution of ammonia. It has been determined that the decomposition degree of copper ammonia and stripped ammonia is more than 98% at the process temperature of 95ºС and duration of not less than 300 minutes. Almost all ammonia transforms from ammonia eluate to the gas phase and then is regenerated in the form of ammonia water. Contained in the eluate copper and silver precipitate in the form of copper hydroxide (II) and silver oxide with a small amount of impurities of precious and rare metals. Based on the results of the conducted studies the process of electrowinning of copper is recommended after dissolving the precipitate. CONCLUSIONS. The studies resulted in obtaining the cathode copper corresponding to the grade M00k. The main electrolysis parameters are: current output is 95%, power consumption is 3100 kWh/t of the cathode precipitate. Silver from the solution is precipitated in the form of sludge and is processed to produce silver ingots.

The PURPOSE of the paper is to study of the process of obtaining Mg-Zn-Y master alloys, determine the list of factors of magnesium-thermic process for optimal process conditions identification. METHODS. The paper uses various modern analysis methods. X-ray fluorescence analysis was carried out using the XRF-1800 sequential X-ray fluorescence spectrometer (Shimadzu). Phase identification was performed with the use of X-ray powder diffractometer XRD-6000 (Shimadzu). The complex thermal analysis was carried out on the STA 429 CD (NETZSCH) installation using the Tg+DTA crucible holder of alundum crucibles with the lids in an argon stream. RESULTS AND THEIR DISCUSSION. Mg-Zn-Y master alloys featuring different content of alloying elements have been obtained as a result of metallothermic reduction of yttrium from fluoride-chloride melts by the magnesium-zinc alloy. СONCLUSIONS. The proposed method of yttrium recovery from fluoride-chloride melts allows 96 to 98% recovery of yttrium. The obtained master alloys are homogeneous and fluid, and can be well poured into molds.

The PURPOSE of the paper is to study the possibility to change the quality indicators of limestone-nepheline charge sinter by the introduction of gypsum anhydrate technogenic additives (GATA). METHODS. The study uses physico-chemical computer modeling based on the thermodynamic analysis, as well as thermoanalytical, electronic and microscopic research methods, an X-ray phase and X-ray diffraction analysis. RESULTS. Introduction of GATA in the proportion from 0.2 up to 2% of the charge weight into the limestone-nepheline charge increases the reactionary ability of components and decreases the sinter formation temperature by 30-70ºС. When entering the reaction, calcium sulfate contributes to the formation of Ca₂SiO₄ and NaAlO₂, as well as the sulfates of alkaline metals - K₂SO₄ and Na₂SO₄. The researches have shown that the introduction of 0.4% of GATA in the charge increases the content of sulfur oxide in sinter from 0.28 to 0.38%, while the raise in the sintering temperature from 1230 to 1290ºC increases sulfate extraction from sintered material up to 67.2 and 89.7% respectively. CONCLUSION. Pilot tests have shown that introduction of gypsum anhydrate technogenic raw materials in the proportion of 0.4% wt of furnace charge increases the output of potassium sulfate by 11900 tons/year as well as reduces the consumption of limestone under charge sintering by 35600 tons/year.

The PURPOSE of the paper is development of a modified methodology of correlation analysis which will allow to obtain accurate enough estimation of the static characteristic coefficients of aerodynamic processes in coal mines. METHODS. The methods used in the study include analytical description of transient gas dynamic processes, the method of transition functions, the moving average method, the probability theory and mathematical statistics. RESULTS. Complexity of the air-gas dynamic processes in the production site, impossibility to account for all the factors affecting them and their stochastic nature determined the need to use the methods of mathematical description and the methods based on the theory of statistical dynamics to specify the characteristics of the above processes. A modified procedure of the correlation analysis has been developed in order to identify the static characteristics based on the experimental data of dependent observations in the normal operation mode. It allowed to obtain sufficiently accurate estimates of the coefficients of static characteristic. Using the software package MATLAB the dependence of the methane concentration on the air flow rate has been obtained. It has been found that under normal operation the air-gas dynamic processes are of an additive character, i.e. production processes of excavating minerals cause the appearance of the components whose statistical characteristics differ from those of purely random processes. It has been experimentally determined that the linearized dynamic characteristics of mining sites in the ventilation mode when the transient gas-dynamic process takes the form of a methane concentration “burst” can be described by ordinary differential equations of the 3- 4 order with constant coefficients while being in the ventilation mode when there is no “burst” of methane concentration on the site - can be described by the equations of the 1-2 order. CONCLUSIONS. The static characteristic of the object of ventilation is determined by the channel “methane concentration - air flow rate”. It can be linearized when the air flow changes in the operating range, i.e. described by linear equations. The type of the static characteristic of the object of ventilation is determined using the comparison of the correlation and dispersion functions. This method enables to obtain a quantitative estimate of the error of the object static characteristic based on the data of facility normal operation.

The PURPOSE of the paper is to implement a genetic algorithm for generating mutually correlated random fields and to study the obtained results. METHODS. The main research methods include the probability theory and mathematical statistics, numerical methods, correlation and spectral analysis. RESULTS. The study has shown the efficiency of the genetic algorithm for generating mutually correlated random fields under various parameters of the random field autocorrelation function. Description is given to the algorithm and the program implementing the genetic algorithm for random fields and mutually correlated fields generation and calculation of their characteristics. CONCLUSION. The efficiency of the genetic algorithm used for generating mutually correlated random fields is shown and its application results are described. The algorithm can be used for image filtering.

The PURPOSE of the paper is to develop a diagnostic model of the electrolysis process in order to organize its safe operation based on a fuzzy Markov chain for assessing the level of information risks. METHODS. The methods used in the research include mathematical modeling and simulation modeling. RESULTS. The fuzzy Markov chain has been examined in order to evaluate the state of the aluminum electrolysis process. Graph nodes corresponding to the system states are characterized by the risk indicators. The latter can be determined as the degree of the fuzzy congruence between the desired and real indicators of system operation. CONCLUSION. The proposed approach can be used to predict the system failure rate for a particular implementation of the information system hardware setup. This will allow to construct a system design technology taking into account the modeling results when formulating requirements for software and hardware resources and finally will enable to select the hardware resources.

The PURPOSE of the study is to find the methods for estimating nonlinear probability dependencies. METHODS.The main research methods are theoretical probabilistic analysis and numerical methods. RESULTS. The behavior of indicators calculated according to the statistical material that presumably contains polynomially connected independent and dependent variables is investigated. The indicators that serve as the basis for calculating the regression coefficients of the polynomial and accurate determination of its order are considered. Particular attention is given to the indicator of the first level, which reflects the contribution of the linear component to the estimated polynomial dependence. CONCLUSION. Indicators can be successfully applied at the stage of preliminary, evaluative statistical analysis for an approximate evaluation of the order and type of a regression polynomial.

The PURPOSE of the paper is to develop the procedure for determining optimal parameters of “driver - vehicle - road - environment” system elements under which system maximum reliability is achieved, i.e. to create a model that allows to identify potentially dangerous elements of the system. The formation of optimal parameters of the “driver - vehicle - road - environment” system is reduced to the task of determining the system parameters under which the probability of accident occurrence is minimal. METHODS. The task set is solved by the method of hierarchy analysis based on the decision-making theory developed by T. Saati and taking into account the mutual influence of parameters. RESULTS. The authors propose a mathematical model on the basis of which the probabilities of a road accident have been calculated on two different sections of the federal road R255 at daylight under similar parameters of the “driver - vehicle - road - environment” system: driver, vehicle and environment. Practical application of the introduced procedure will lower the probability of road accidents by reducing the accident rate of priority parameters of the “driver-car-road-environment” system. CONCLUSIONS. The article provides a mathematical model that allows to determine such parameters of the “driver - vehicle - road - environment” system under which the probability of an accident is minimal. The accident rate which takes its values depending on the actual values of a particular parameter and the priority vector that defines parameter importance has been used to determine the probability of an accident. Reduction in the value of the priority parameter accident rate reduces the accident probability. A correlation model describing the dependence of accident probability on the driver, vehicle condition, roadway condition, traffic intensity including the speed of the vehicle and distance between the vehicles for different road sections, as well as road illumination and weather conditions has been obtained.

The article analyzes the situation connected with the transition of the operation sphere of transport and technological machinery (TTM) to the market principles of management. Obtaining of high economic results of operating and construction enterprises requires to develop and introduce into the practice up-to-date and more economical approaches and methods of machinery operation. The PURPOSE of the research is to improve the efficiency of TTM operation and competitiveness of the carried out mechanized works through the optimization of processes and costs associated with the application of contemporary machines as intended and machinery maintenance. METHODS. The effectiveness of the TTM operation system is determined on the basis of the process analysis in a complex organizational and technological system implementing a machine service life. The structure of the complex organizational and technological system of TTM operation as well as the interaction and reciprocal effect of the subsystems constituting it are described using a synergetic approach. RESULTS AND THEIR DISCUSSION. It is determined that the purpose of TTM operation at all levels is as follows: 1) to optimize the service on the use of both individual machines and their complexes in order to fulfill the corresponding works at the sites taking into account their specific features and achievement of the acceptable level of income; 2) to tighten the control of machinery operation modes when functioning in order to achieve the acceptable level of income; 3) to provide technological support and restore the serviceability of machines; 4) to provide machines with qualitative operating materials; 5) to systematize the transportation (movement) of machines to the sites; 6) to save and keep machines in the periods when they are not used for intended purposes. CONCLUSIONS. The operation of transport and technological machines must represent by itself a single technological process which includes the technological processes of machinery intended use, technological control processes, technological processes of machinery technical operation (processes of maintenance and repair). In market conditions all these processes are entrepreneurial as the goal of the most of them is making profit. Therefore, it should be recognized that the third synergetic paradigm of transport and technological machinery operation has already been formed.