Vol 30, No 2 (2022)

Informatics, Computer Science and Control

Automatic control system of modular induction complex for heating viscous liquid

Danilushkin A.I., Danilushkin V.A.


The article deals with the controlling problem for the indirect induction heating process of viscous non-conductive liquids during their transportation through a pipeline system. Complex nonlinear processes occurring in the system «induction heater – metal pipe wall – fluid flow» characterize the plant. Due to the complexity of the process and the impossibility of obtaining transfer functions in an analytical form, we use transition functions obtained by calculation using a numerical model to evaluate the dynamic properties of the plant. The significant technological restrictions imposed on the process parameters complicate the effective control system implementing. These restrictions include, first of all, the restriction on the maximum temperature of the liquid boundary layer in contact with the heat transfer surface of the pipe. The technological requirements implementation is only possible in a multi-section heater with autonomous power sources. Significant non-uniform temperature of the fluid flow due to low thermal conductivity makes necessary distributed temperature measurement to estimate the mean temperature in the controlled flow cross section. The study of the dynamic properties of the heater is carried out with relation to the liquid temperature at certain fixed points of the flow cross section at the outlet of each heater section. It is noted that an adequate assessment of the mean flow temperature over the cross section, it is sufficient to have four control points for which the parameters of the transfer functions are determined. To calculate the mean temperature over the flow cross section, the experimentally obtained dependence is approximated by a piecewise linear function consisting of straight-line segments with ends at the temperature measurement points. The paper presents a structure model of the plant consisting of three heating sections. The block diagram of each section of the plant is a set of elementary links – aperiodic and delay links. To study the dynamic properties of an automatic control system for a multi-section heater, a dynamic model of the system was used implemented using the programming and numeric computing platform MATLAB® and environment for modeling dynamic nonlinear systems - Simulink®.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(2):6-20
pages 6-20 views

Problem-oriented model of the technological process of surface induction hardening

Pavlushin A.V.


The paper presents a nonlinear two-dimensional numerical model of the temperature and thermal stress fields within a steel billet of complex geometric shape in the surface induction hardening process. The problem-oriented model developed in the ANSYS Mechanical APDL software package can be integrated into the optimization procedure for designing an induction coil and controlling the heating and cooling stages. The following steps of modeling are described: setting the properties of materials, the geometry building and overlaying the FE mesh, setting the boundary conditions, and setting up the model calculation algorithm. To simulate the heating stage, the interrelated electromagnetic, thermal, and elastic-plastic problems are solved, which results in obtaining the spatio-temporal distributions of electromagnetic heat sources, temperature fields, and thermal stress fields over the workpiece volume. The model of the heating stage is oriented for further use in the numerical procedure of parametric optimization of the design and operating parameters of the induction installation to obtain the highest possible uniformity of the temperature distribution, on which the quality of the microstructure of the hardened layer depends significantly. To simulate the cooling stage, thermal and elastic-plastic problems are solved, providing the spatial-temporal distributions of temperature fields and thermal stresses over the workpiece volume. As a cooling (quenching) medium, a water shower is used after induction heating to form a martensitic microstructure of the surface hardened layer. The simulation of the cooling stage is performed using the temperature-dependent equivalent surface heat transfer coefficient, which greatly simplifies the modeling process. The model of the cooling stage can be integrated into the numerical procedure for solving the problem of optimal control of the spraying device, which allows for improving the hardening quality by adjusting the intensity of the water supply.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(2):21-34
pages 21-34 views

Optimization of the compounding process of petroleum products

Rogachev G.N., Trufanov Y.S.


The process of compounding, mixing several types of fuel to obtain products of a given quality, makes it possible to obtain gasoline with the required properties. Traditionally, the preparation of gasolines takes place in tanks. The components are high-octane additives, gasoline components from process plants and components from other tanks. Compounding is the final process for the preparation of gasoline, so its preparation and conduct determine the quality of commercial products. The existing method of compounding in production is a multi-stage operation, including determining the amount of a mixture of components in a tank, selecting the amount of additives, mixing all components and additives, laboratory analysis and issuing a quality certificate for the tank. This method can be optimized by eliminating a number of operations and calculating the required number of components before they are sent to the tank. The task of compounding can be formulated as follows: it is required to prepare the required amount of commercial gasoline in a specific tank with a known quality and amount of residue. In addition, in the process of developing a commercial gasoline formulation and technology for its preparation, it is desirable to use all available gasoline fractions to the fullest extent with minimal use of the most expensive part of commercial gasoline - additives. The problem of optimizing the component composition of commercial gasoline is solved in the work by the method of linear programming and is based on the quality indicators of the available components and the task for the plant to produce certain brands of gasoline. Examples of determining the most expedient and cost-effective ratio of components for some batches of gasoline are given. The problem of choosing a specific tank is formulated and solved, in which, under the current restrictions, it is possible to prepare a product of the required quality with a minimum consumption of the additive. It is concluded that for transparency and accuracy of accounting, the implementation of specific production operations for the preparation of commercial gasoline must be carried out according to the method of operational accounting. It is recommended to use the methodology of step-by-step accounting when compounding marketable petroleum products, which can significantly improve the quality of production accounting.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(2):35-47
pages 35-47 views

Multicriteria evaluation of the comparative efficiency of generating equipment

Sagitova L.A.


Since energy systems operate in conditions of constant changes in the external environment and are complex organized systems, this leads to the need to make complex management decisions. To improve the efficiency of power facilities, an algorithm for the decision support system is proposed. The algorithm allows to optimize the work of energy enterprises, taking into account the peculiarities of the joint production of heat and electricity. The algorithm is based on the principle of a systematic approach to resource saving in energy production. To assess the comparative efficiency of equipment, a methodology was proposed that takes into account an expanded set of characteristics of the operation of power equipment using the DEA multi-criteria assessment method (Data Envelopment Analysis). Generalized criteria for the efficiency of the operation of power equipment were formulated, characterizing the efficiency, manufacturability and environmental friendliness of the operating modes of boilers. A global efficiency criterion has been formed that allows for a comprehensive assessment of the quality of equipment operation. The application of this technique is demonstrated on the example of the TP-230 boiler. The use of the DEA methodology makes it possible to optimize the choice of boiler operation modes, taking into account their actual state. The proposed decision support system algorithm can be used to analyze similar power facilities.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(2):48-59
pages 48-59 views

Electrical Engineering

Investigation of thermal field of the limited-angle torque motor

Ivannikov Y.N., Ovsyannikov V.N.


A limited-angle torque motor is the electrical motor which be used in applications with specific requirement of shaft torque. The particularities of work of torque motor are high stability of shaft torque within operating angle. This singularity is based on used of ring winding and smooth-core armature construction. That decrease torque ripple and increase accuracy of rotor position control. These key points do a torque motor required in applications of high accuracy angular stabilization. For example, they are vehicle-born equipments, actuating unit of robots, industrial manipulators and so on.

Used ring winding and smooth-core armature lead to increase non-magnetic gap and thereby to complication design of excitation system. Under such conditions for creation required gap flux density use rare-earth permanent magnets. Nd-based magnetic alloys achieved prevalent recently and often they use in electrical machines. Vital limitation these alloys are high temperature dependency that require calculation a temperature field at the stage of magnets choice. Moreover design of torque motor represents embedded system which have single shaft that decrease of backlash and single housing with actuating unit. For control of torque a torque motor have variable supply source which change out voltage by means of pulse-width modulation. Therefore calculation of temperature field with account for magnetic losses and eddy current loss in magnets caused by used pulse-width modulation, single housing is relevant objective for advance of characteristics of torque motor.

The paper presents results of numerical simulation of transient magnetic task and steady-state heat transfer task. Consequently decision of transient magnetic task was got quantity and distribution magnetic losses in the core and eddy current loss in permanent magnets of torque motor caused by pulse-width modulation. These results were used in the capacity of initial condition in task of steady-state heat transfer. As part of steady-state heat transfer task was specified influence magnetic losses and presence housing over temperature field. Steady-state heat transfer task was modeling in 2D and 3D statement. Through analysis and comparison of results 2D and 3D statement was got limitations of 2D statement in terms of concerned torque motor.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(2):60-72
pages 60-72 views

DC linear motor for stabilization system of precision objects

Makarichev Y.A., Ratzev Y.A.


Linear DC motors (LDPT) with a limited armature stroke are used in mechanisms that reciprocate the working body or stabilize its position in servo systems. The use of LDPT instead of rotary motion motors with a converter in the form of a crank mechanism, a screw pair or other similar mechanical systems leads to a significant simplification of the kinematic scheme, an increase in efficiency and, as a rule, an increase in the accuracy of the complex and its reliability.

However, there are a number of problems in the creation of LDPT, which hinder the introduction of these certainly promising electrical machines in some specific areas of application. So, linear motors of stabilization and vibration protection systems of precision optical systems, in addition to providing a given nominal force, must have a stable power characteristic over the entire range of the armature stroke. In addition, the motor must have high electromagnetic and electromechanical speed. Remain relevant for engines and minimal weight and size characteristics.

The article presents some issues of constructive solutions for high-speed LDPT, as well as methods for their calculation and mathematical modeling. The results of numerical simulation of the electromagnetic field of the engine are presented and, based on the data obtained, its static power characteristics are determined.

Verification of theoretical positions was carried out in the course of experimental research of an engine designed and manufactured at one of the specialized enterprises of an industrial partner. Tests showed good convergence of the calculated and experimental characteristics of the machine. The developed engine has no analogues among machines designed for these purposes.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(2):73-84
pages 73-84 views

Mathematical model of a digital AC servo drive with different discritization periods in regulators taking into account

Rokalo D.Y.


The article deals with a digital AC servo drive, the structural construction of which differs from traditional slave control systems. The block diagram of the electric drive is given in the transition to discrete transfer functions. The transfer functions of digital controllers are determined taking into account the proposed algorithm for their operation. A computational model for the program "Matlab Simulink" is presented, which allows to plot the transient process for the control action in the developed digital AC servo drive when implementing controllers on programmable logic, taking into account different sampling periods. The transfer functions of an asynchronous electric motor together with a power converter and a zero-order extrapolator are obtained. A discrete transfer function of a closed-loop servo drive is found, taking into account different sampling periods in controllers. Field experiments were carried out in an experimental setup based on a SK36-1202 turntable equipped with a 1FK70605AF71 synchronous motor with a Simovert Masterdrives Motion Control frequency converter. The results of computer simulation are compared with natural experiments.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(2):85-99
pages 85-99 views

Analysis of converter circuits used to power the phases of switched reluctance drives

Smachny V.Y.


Switched reluctance drive (SRD) is a promising electromechanical energy converter. It has a simple design of the active part, is reliable in operation, manufacturable, and has high-energy performance. An important element of the SRD is a converter that regulates the phase current. The performance, size and cost of the SRD largely depend on the type and power of the converter chosen.

The article analyzes the existing topologies of SRD converters, the characteristics and features of the work of converters implemented according to these topologies, and classifications of topologies of converters are given.

A new single-switch topology of the converter is proposed, containing 2 independent galvanically isolated DC voltage sources, 2 capacitors, a diode, a semiconductor switch and a stator winding of the Switched Reluctance Motor (SRM) phase, divided into 2 half-windings. Analysis of the characteristics showed that the proposed circuit has all the advantages necessary for a modern SRD converter: it can be used for SRD with any number of phases; the circuit provides independent phase control; allows you to implement 3 main algorithms for the operation of the converter – the possibility of forming all three voltage circuits: positive, negative, energy conservation.

The main area of application of the converter with a new topology is determined - these are electric drives of mechanisms, for which, in addition to energy efficiency, the tasks of ensuring their reliable operation, as well as reducing the cost of technical solutions used in practice, are also relevant. Reliability increase is achieved due to the ability to carry out full redundancy of all components of each phase, including power supplies, when creating an electromagnetic torque on the shaft, cost reduction is achieved through the use of one switch element per phase.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(2):100-121
pages 100-121 views

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