PNRPU Bulletin. Electrotechnics, Informational Technologies, Control Systems

The induction motor with ring windings (IMRW) is designed for the processing of nuclear waste, the first prototype of IMRW was created by a scientific group of the Department of Electrical Engineering of the Ural Federal University together with the “Uralelectromash” plant in Kamensk-Uralsky. The advantage of this motor is stability to high levels of radiation and temperature due to the use of ceramic insulation for the stator windings, but tests of the prototype showed that the maximum and starting moments of the engine are less than the required by the technical specifications, and therefore a search for solutions to improve engine parameters is necessary. Purpose of the study: assessment of the effect of the layered structure of the IMRW stator core on the operating flux and leakage flux of the machine. The analysis of the electromagnetic core showed that the design feature of the magnetic system of an induction motor with ring windings leads to the appearance of two components of the magnetic flux - axial and radial, thus it is necessary to consider the effect of the layered structure of the stator core on the magnetic resistance for the axial component of the magnetic flux. The oxide or varnish coating of the steel sheets of the stator core, as well as the technological gaps between the sheets caused by pressure testing of the core during manufacture, increase the magnetic resistance, therefore, reduce the working magnetic flux in the air gap, the starting and maximum moments of the engine. Methods: as a solution to reduce the magnetic resistance in the axial direction of the magnetic flux and improve the output characteristics of the machine, it is proposed to use magnetic shunting in the stator yoke. Results: Modeling a motor with ring windings using a "ANSYS Maxwell" was provided. It allows to evaluate not only the effect of the layered structure of the stator core on the axial component of the magnetic flux, but also the efficiency of using magnetic shunts, as well as to quantitatively calculate the values of the magnetic flux at each section of the magnetic circuit and give recommendations for further improvement of the engine design. Practical relevance: The results obtained can be used to obtain a second prototype ADCO with improved mechanical characteristics.

Installations of electrodynamic separation in a traveling magnetic field are used in technologies for processing solid waste of production and consumption. They are used for the extraction of non-ferrous metal inclusions from the non-metal stream, as well as for the induction sorting of non-ferrous scrap and alloys. The article discusses the installation, which consists of a conveyor that moves the processed materials, and a linear inductor located under the conveyor belt. Purpose of the study: Increasing the technological and energy efficiency of electrodynamic separators based on linear inductors. Results: It was shown that to increase the degree of metal recovery from the waste stream without increasing energy consumption, it is advisable to use a linear inductor of a modular design. In this case, the modules are displaced relative to each other along the movement of the conveyor and the movement of the extracted particles. In the case of using three inductor modules, a possible rearrangement of the winding phases on separate modules, which ensures the symmetry of the phase currents of the separator. The equalization of the phase currents allows the reactive energy of the inductors to be fully compensated. At the same time, energy losses in the power supply system are reduced. The possibility of choosing the parameters of linear inductors at the design stage is shown, taking into account the achievement of a minimum consumption of the total power consumed by the separator from the network. Taking into account the possibility of compensating the reactive energy of the inductors, it is proposed to proceed to the selection of the parameters of the linear inductors according to the condition of achieving a minimum of the active power of the separator. The given examples of calculations of an experimental industrial model of an electrodynamic separator show that with this approach it is possible to adjust the parameters of the inductor, which provides an improvement in the technological and energy characteristics of the separator.

The article is devoted to the consideration and comparison of various magnetic structures of rotors used in permanent magnet synchronous motors. In many areas of industry, operations performed on equipment require precise mechanical movement, whether assembly, grinding, welding operation, different positioning systems, like solar trackers. The classic implementation of such movements is to the use of a reduction electric drive on individual equipment nodes or to the installation of one drive for several operations (the concept of a “main” drive). However, in gears and converters to linear motion, there are always backlashes and gaps. In addition, the presence of additional flexible bonds introduces nonlinear perturbations into the movement of mechanisms. The development of modern electric drives and control systems allows them to abandon the use of kinematic converters and combine the motor with the load directly. An electric drive without the use of kinematic converters is a direct (gearless) electric drive. In such a drive, the force is transmitted without loss of speed and accuracy, there are no additional non-linearities and elasticities. In addition, due to the absence of wear on the mechanical parts, direct drive becomes more reliable than reduction drive. The most common in direct electric drives are permanent magnet synchronous motors (PMSM) due to their best characteristics compared to other types of motor. Purpose: to consider the fundamental differences in the structures of the PMSM rotors. Methods: graphical study of magnetic structures, the use of PMSM equivalent circuits. Results. The influence of the arrangement of magnets on the characteristics of the motor is considered. Authors described the reluctance torque arising due to a rotor polarity in terms of its influence on motor control. A coefficient introduced that characterizes the anisotropy of the magnetic properties of the motor. Angular characteristics for different motor types and their influence on the stator current angle in motor control process shown.

It would be useful for modern projects using neural networks to unload computing centers by distributing computing power for neural network recognition in a distributed network. The aim of the study is to develop a method for synthesizing devices for implementing artificial neural networks on FPGAs and microcontrollers focused on fog computing. The basis for the creation of the devices in question will be an artificial neural network, which will need to be divided into several blocks. Each of these computing units will be executed on a separate physical device, communication between them will be carried out using standard channels and protocols. The research methodology is based on the analysis of information about existing neural networks and mathematical modeling of a neural network that will be suitable for operation in the fog computing mode. As a result of the research, it is planned to obtain a mathematical model of a neural network and a method for dividing a neural network into blocks that will work on terminal devices, and this method will also be tested on a test cascade of computing devices. The article considers the existing classes of artificial neural networks, based on the review obtained, the parameters of the networks with which work will be carried out within the framework of this study are selected. A mathematical model has been developed that allows a set of blocks to be obtained from a conventional neural network that is exclusively executed on one computing device, the sequential execution of which on a cascade of devices will lead to results similar to the results of the original network. Input parameters for the separation method have been selected, which will allow further experiments with devices.

Currently, the most common three main types of electrical machines - alternating (synchronous and asynchronous) and direct current. Each of them, due to the peculiarities of its design, has certain starting methods when operating in engine mode. The object of research in this article is a synchronous machine, which is of particular interest in comparison with other types of electromechanical converters due to its intensive use in power electric power plants not only as a source of electrical, but also mechanical energy, for which it becomes necessary to start it. There are several ways to start a synchronous motor, each of which has its own advantages and disadvantages, for the identification of which the developed models of a synchronous machine and various types of sources of electrical energy were studied. Studies have shown that the most interesting are the frequency methods of starting a synchronous machine, since non-interference in the design of the machine will allow its continued operation. Purpose of the research: development of a model of a synchronous motor and various types of sources of electrical energy; investigation of the starting characteristics of a machine connected to various power sources. Methods: studies of the starting characteristics of a synchronous motor from various power sources were carried out in the Matlab (Simulink) environment, for which mathematical models of a synchronous motor and three power supplies were developed. Results: studies have confirmed that of the four ways to start a synchronous motor, the frequency one really has a number of advantages over the others. The time of the transient process with such a start of a synchronous motor is significantly reduced, therefore the efficiency of the machine is the greatest, since it quickly reaches the nominal mode and begins to perform its functions. The smallest thermal impulse observed in this case indicates low thermal losses, which also has a beneficial effect on the operation of the synchronous motor and power supply. However, the frequency start of a synchronous motor has a significant drawback - the starting current is of great importance, commensurate with the magnitude of the stator current during direct start. Practical significance: the analysis of the data obtained during the research, namely the start-up time, the magnitude of the thermal impulse and the critical moment, will allow in the future to optimally tune electric power systems containing synchronous motors in order to increase their efficiency, and also simplify the process of identifying the parameters of a synchronous machine, spectral and wavelet analysis of their transient processes.