The simulation system MTSS is a visually interactive process-oriented discrete simulation system. With use of the simulation system MTSS a number of models of mining machines, and models of coalmine subsystems such as a working face, an underground conveyor network, a pumping subsystem, and a power supply subsystem were developed. To combine these heterogeneous models in the simulation system MTSS the possibility of distributed simulation is implemented. To implement this possibility, the High Level Architecture standard and Runtime Infrastructure Pitch pRTI Free was used. As an example of the use of distributed simulation, a federation consisting of two federates from a simulation model of a coalmine working face and a simulation model of a belt conveyors network of a coalmine is presented.
The cooling of surfaces that perceive high heat flows (more than 7 MW/m2) at the current rate of development of the energy sector will become one of the main problems of the near future. Already at the moment, during the construction of the experimental thermonuclear reactor ITER, located in the Center for technological research of Cadarache, France, there is a need to divert the heat flux density of about 10 MW/m2 to maintain stable operation of the reactor. In this article, it is proposed to use a method of heat exchange intensification using a two-component dispersed flow. The effectiveness of this cooling method is due to the use of the latent heat mechanism of the phase transition instead of the convective heat transfer mechanism. The paper describes the experimental setup, the method of measuring and conducting the experiment, as well as the results obtained. The highest value of the diverted heat flux density obtained as a result of processing experimental data is 11.2 MW/m2, with a coolant flow rate of 0.025 kg/s. The experimental data results indicated in the article reveal the possibilities of using a dispersed two-component flow and indicate the high efficiency of the proposed cooling method.
Usually, the generation of electricity from the conversion of a mechanical rotation energy requires the adjustment of the level of not only the output power, but also the voltage. Changes in the speed of rotation of a generator rotor, as well as load drops and surges, can lead to a deviation of the voltage value from the nominal one. That is why generators with permanent magnets on the rotor are of limited use where stability of the output voltage is required. This article describes the design of a brushless generator which does not have the disadvantages of currently used generators with permanent magnets, and with excitation windings on the rotor. The proposed generator does not have windings on the rotor. Accordingly, it does not have brushes, and can work for a long time without any maintenance. It can be used in wind turbines, generators of ships, and superconducting sources.
This paper presents a methodology for verification of digital substations using real-time simulation. The behaviour of digital substations requires new forms of verification and traditional methodologies do not provide this capability. In addition, modern electrical networks impose new demands on control and protection systems, which must be much more finely tuned to meet these new challenges, achieving greater accuracy and integrity in the operation of each constituent element. The challenge of the energy transition, which includes distributed generation, electric mobility and energy storage, means that the electricity grid must be responsive and ready, becoming increasingly reliable, efficient and resilient. The proposed methodology is a verification of the implementation of digital substation automation levels for control and protection, for different architectures and communication devices based on IEC 61850, which demonstrates the need and benefits of verifying automation, control and protection in the integration of digital substations in electrical networks, using real-time modelling, reducing maintenance time and cost and improving efficiency and reliability in the operation of equipment before commissioning and future expansion.
The paper proposes a methodology for creating a dynamic model of a flow heater with time-varying flow rate and heat transfer coefficient. The first-order hyperbolic equation is used as the mathematical description of the heating process. The numerical model of the heating process is obtained using the spectral method of analysis and synthesis of distributed systems. The orthonormal function basis is used for the transition to the state space. A method for the consideration of non-zero boundary conditions is proposed. The state-space model of the flow heater is obtained and its implementation in Simulink using the MATLAB S-Function block is proposed. The results of the study of the obtained model are presented in the article. The dynamic behavior of the model is compared with the analytical solution of the hyperbolic equation. The dependence of the model accuracy on the dimensionality of the state vector is investigated.
The principles of a risk-based approach have not yet been fully implemented in the operation of overhead transmission lines (OHTL) due to the immaturity of the methods and, above all, the lack of diagnostic data on the actual and forecast state of OHTL. The contaminated insulator flashover is the cause of 23-45% of accidents in OHTL. Despite the fact that the accumulation of pollution on insulators is predictable enough, risk-oriented diagnostics of linear insulators is not available yet. This paper provides an analysis of existing methods for linear insulators diagnostics to quantify the insulator state, appropriate for the risk-based approach implementation.
The problem of steering underactuated autonomous underwater vehicles in the horizontal plane under the action of uncontrolled constant ocean currents into the vicinity of a given object is considered. Controls are formed by measurements of the angle of sight characterizing the position of the object (for example, its centroid) by images coming from a video camera or an acoustic sensor. It is used the pure-pursuit guidance law. The proposed approach is based on a stability concept of terminal systems with a singular point, a generalization of the Lyapunov function method, asymptotic analysis in a vicinity of the singular point for increasing the initial range.
This article considers increasing the transmission capacity of a 110 kV overhead power line by the artificial increase of natural loading and reducing surge resistance through shunt capacitive compensation means to maintain a balanced electromagnetic mode when the overhead line does not consume the reactive power from the main substation required to form the self-magnetic field. The authors determine the shunt capacitive compensation degree necessary to increase the natural loading of the overhead power line to the transmission capacity level restricted to the rated temperature rise current density of the phase conductor. It is shown that the practical implementation of transverse capacitive compensation can be carried out using mast capacitor banks, the installation of which does not require overhead line reconstruction.
The spectral properties of musical works as well as their impact on the body of a person were explored in this work. The authors applied the Fourier transform for the spectral analysis of a musical composition. The problem of the effect of music on the body of a person is relevant from ancient times. Already at that time, it was established that with the support of music it was possible to generate pleasure, remove pain, and also cure fundamental diseases. Avicenna used music very effectively in the treatment of the mentally ill. The Fourier transform is a given general mathematical mechanism (1942) used by audio compression standards like MP3 among many other applications. The inverse Fourier transform decomposes the sign into the elements of its frequency in a clear way, just as the human ear cultivates pulsations in order to perceive individual tones. The basic principles of the concept of music, the implementation of also the conclusion of a discontinuous Fourier transform, but in addition the application of the analysis of audio files in order to extract spectral data were discussed in this article. The device AIMT-1 was used in the work. This device frequency modulation used with a carrier frequency of 4.1 GHz and a deviation frequency of 26 MHz. Microwave radiation from the sun (society) was used as a control signal. In this case, it was necessary to change the type of commanding signal to music.
The authors propose expressions for the calculation of the total losses in power supply system equipment used for the electric power transportation. Unlike the conventional methods that calculate losses separately for components and equipment types, the expressions developed take into account the entire set of the power supply system and load elements connected in one operating mode. The developed expressions are based on the equivalent circuit of the power supply system where the three-phase double-winding power transformer uses a reduced symmetrical T-shaped equivalent circuit of one phase. The analysis proves that the separate treatment of the calculation of losses in the power supply system for the power line and double-winding power transformer without consideration of their mutual influences results in calculation inaccuracies. The authors assessed the calculation error in losses and total power consumption values obtained using the expressions suggested and compared them with the mathematical model. The authors proved that the use of the developed expressions for the calculation of the total losses in power supply system equipment used for the transportation of electric power results in increased calculation accuracy.
Up to now, scientific practical research works are being carried out on the improvement of signalling, centralization and blocking field devices and blocks, control of the vacancy of peregnos using new generation microprocessor technologies, and their localization in the field of railway transport. In this direction, one of the most necessary scientific tasks is the improvement and localization of control systems by creating control devices used in the control of railway sections on the basis of microprocessor elements. In the process of ensuring traffic safety, it is necessary to improve the devices for counting the axles of wheel sets of a train set based on digital devices, which are the main components of automation and telemechanics systems and are used to monitor the condition of railway sections.
Currently, due to the problems of hydrocarbon fuels and environmental ecology, much attention is paid to the research and development of alternative energy sources, in particular, capacitive energy storage. Capacitive storage devices are widely used in various fields of science and technology due to their high specific power and ability to quickly accumulate and release energy. In recent years, capacitive energy storage devices with high specific characteristics have been developed, in particular, molecular energy storage devices, ionistors, capacitors with a double electric layer. In this regard, much attention is paid to chargers, which should not only provide a fast charge of capacitive energy storage devices, but also have high energy parameters. This article is devoted to the study of the phased charge of energy storage devices, in which the maximum energy parameters are provided.
One of the most important indicators of the quality of radio information transmission systems is noise immunity. The most significant impact is caused by interference exceeding the level of the useful signal. In the author's previous work, a method of digital signal processing was published to combat interference of this kind. The article describes a mathematical and software model of two-channel synchronous signal reception with the results in the form of a dependence of the probability of block errors in the transmitted information on the signal / (interference + noise) ratio, where the result of the noise immunity of the system to minus 26.5 dB was achieved. However, like any other method, the proposed one has its weaknesses. This work describes and analyzes the main factors affecting the effectiveness of the method under study.
Ensuring continuity and reliability in the power supply systems of autonomous special-purpose facilities is an urgent task. A promising solution is the use of the latest types of batteries in the power supply systems of such facilities based on static uninterruptible power supplies. The requirements for the power supply systems of such facilities have a number of specific conditions due to the characteristics of these facilities. The aim is to develop power supply systems using static uninterruptible power supplies (UPS) based on fully controlled current inverters. Analysis of the existing power supply systems showed the imperfection of such schemes and does not provide complete independence of the facilities from external power supply. Comparative characteristics of isolated power supply systems built on the basis of diesel generator sets (DGS) and UPS are given. Both types of sources are currently used in power supply circuits for remote objects. The importance of the task is to ensure the reliability of power supply, which is ensured when using modern types of batteries and diesel generator sets can be completely excluded from the power supply scheme. A technical solution has been proposed - the use of a UPS made according to the «online» technology with the conversion of the number of phases of the supply voltage «three in one». A feature of the considered power supply system using a UPS is its complete independence from the number of parallel operating UPSs, since synchronization with the network is performed at constant voltage.
In this paper a microstrip line (MSL) with rectangular and rounded conductor shapes is investigated. For each conductor shape, simulation in the TALGAT system is performed and values of the per-unit-length capacitance (C), the per-unit-length capacitance in vacuum (C 0 ), the per-unit-length delay (τ) and the impedance (Z) at different values of segment length (S) (with uniform auto-segmentation of all conductor and dielectric boundaries) and the conductor width (w) are calculated. Convergence results for the two conductor shapes are presented. It is found that with decreasing S the maximum changes decrease from 1.6% to 0.3% on average for ΔC, ΔC 0 and ΔZ and from 0.7% to 0.06% for Δτ. Increasing w from 0.2 mm to 0.4 mm improves the convergence for all characteristics of the MSL.
The paper addresses the construction of an integral model in the form of a quadratic Volterra polynomial based on real-life data corrupted with errors in measurements of the input signal of a dynamic system. The algorithm of polynomial identification is based on the reconstruction of integrals from the Volterra kernels using piecewise constant test signals. The approximation of the integral model is performed by the product integration method generalized to the case of multidimensional convolutions. A smoothing cubic spline is applied to increase the stability of the computational algorithm to measurement noise. The results of a computational experiment in modeling the dynamics of heat engineering equipment in a local section of the steam-water circuit in the power unit of the Nazarovo GRES are presented.
Cable routing for interconnection of power substation equipment is calculated considering loads caused by short-circuit, dead weight, wind, etc., but does not take into account additional conditions depending on final installation, or exclude loads such as those present in high-rise buildings. areas. seismic activity, aspects that would complement the cable deformation calculation, on the other hand, design efforts are generally not associated with 3D models, as they use only reference points and "splines" to determine Knowing the approximate deformation of the cable is important for verifying electrical distances, minimising possible inconvenience during the construction phase. This paper presents the integration of various load models for cables in a finite element representation with the SAP2000, including final installation conditions and seismic loads according to IEEE 1527, guaranteeing connection stability, electrical safe distances and equipment integrity. In addition, the deformation results are linked to an application developed in Dynamo-Python to augment the BIM model in Revit. With the proposed integration, the expected deformations are obtained for small offsets, presenting a better path correction and stress calculation, but for larger offsets representative differences in measured forces are obtained, and this aspect needs improvement.
We synthesized and analyzed an intelligent control system based on an adaptive control loop with an ideal model of a second-order inertial object in MatLab/Simulink. We also considered the construction of a control loop with a proportional-integral controller (PI-controller) which is adjusted using one time constant and overshoots by 4.2%. A self-tuning automatic control system can compensate for changes in the initial parameters of the control object and for calculation inaccuracies. We found that deviation of the time constant T 1 =50–120s and the transfer coefficient Koc = 2–3 led to 12.7% overshoot by the PI-controller and 4.2% for the adaptive PI-controller. Regulation time was 745.4 and 357.5 seconds, respectively. The experiment showed that for objects with dynamic constants that are highly dependent on external or internal factors (such as heating elements) the control process is oscillatory, and the control speed can be significantly affected in the absence of a self-tuning system.
Modern technological development keeps the course on alternative energy, the use of energy storage and the development of energy-saving technologies. For industrial enterprises of ferrous metallurgy the presented aspects are very relevant, but at the same time cause certain difficulties for their development and further implementation. This article considers the introduction of energy storage and their contribution to increasing the share of renewable energy sources in the energy supply of industrial enterprises of ferrous metallurgy. It is supposed to consider two mechanical accumulators popular in the literature (after hydroelectric storage power plants): a tower-type gravity accumulator and a super flywheel. Their generalized description, principle of operation and evaluation of applicability in conditions of industrial power grid are given. The main part of the work is devoted to a preliminary calculation on the choice of accumulators for installation as part of the power grid of a metallurgical enterprise containing both calm and sharply variable load. As a result, the influence of accumulators on electric load schedules was determined and the approximate possibilities of these accumulators for increasing the efficiency and reliability of the power supply system of an industrial enterprise were calculated.
This article describes a solution for automating measurements on CNC machines equipped with automatic measurement tools using a vision system that simulates stereoscopic vision. The proposed method of measurement allows non-contact determination of the approximate position of the workpiece on the machine to fill in the parameters of measuring cycles. A three-stage algorithm for image processing by a software module of such a system is described, including recognition of the area with the workpiece, automatic correction of input images for successful contour recognition, determining of the contours of the workpieces and their geometric parameters, as well as calculation of the approximate dimensions of the workpieces relatively to the marks applied to the machine worktable beforehand. The calculated dimensions must be transmitted to the CNC system of the machine to run a parameterized program that calls a measuring cycle that clarifies the position of the workpiece on the machine. A model of the vision system has been implemented and tested.
