scholarly journals Developing New Thermal Protection Method for AC Electric Motors

Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 51
Author(s):  
Igor V. Bochkarev ◽  
Ivan V. Bryakin ◽  
Vadim R. Khramshin ◽  
Aida R. Sandybaeva ◽  
Konstantin V. Litsin
Keyword(s):  
Thermal Protection ◽  
Thermal State ◽  
Block Diagram ◽  
Experimental Studies ◽  
Phase Method ◽  
Technical Solution ◽  
Electric Motors ◽  
Protection Method ◽  
Direct Measurements ◽  
Digital Temperature Sensor

Monitoring the thermal state of windings of electrical machines is a backbone for protection from unacceptable overheating. A large number of different methods and systems aim to solve this problem. This article discusses the main known methods of thermal protection of electric motors and provides their comparative analysis. This paper shows that the most promising methods are those based on control of the current active resistance of the stator winding, as its value uniquely depends on temperature. It is demonstrated that the known methods have a number of disadvantages. A new phase method for thermal protection of AC motors is proposed. The method is based on the fact that a temperature-induced change in the active and reactive components of the winding impedance causes a corresponding change in the angle between the vectors of phase voltages and currents. This allows for thermal protection by controlling the change in this angle. This article provides tabular analytical substantiation of the proposed method, which is based on the direct measurements of voltage and current and the subsequent algorithmic calculation of physical values functionally related to the sought angle. The authors develop a structural block diagram of a device that implements the proposed thermal protection method. All relevant experimental studies were carried out. In this case, a small-sized electronic thermometer with a remote digital temperature sensor connected to the USB port of a personal computer was used as a temperature meter. The results obtained confirm the functional capability and efficiency of the proposed technical solution.

scholarly journals INCREASING THE EFFICIENCY OF THERMAL DIAGNOSTIC CONTROL OF ELECTRIC MOTORS

2020 ◽  
Vol 4 (157) ◽  
pp. 163-171
Author(s):  
S. Yesaulov ◽  
О. Babicheva ◽  
M. Kovalik
Keyword(s):  
Initial Data ◽  
Heating Temperature ◽  
Experimental Studies ◽  
Measuring Instruments ◽  
Technical Diagnostics ◽  
Technical Solution ◽  
Electric Motors ◽  
Accurate Identification ◽  
Computing Device ◽  
Measuring Device

The article considers the cause of electromechanical equipment heating (EMЕ) during its operation. It has been reflected the well-known malfunctions of electric motors, that lead to overheating and failure of their individual components. Based on the analysis of existing methods of thermal diagnostics, It has been considered the trends in the creation of devices for monitoring thermal processes and it has been noted the reasons that restrain the use of technical diagnostics tools for thermal faults during the operation of EME. The purpose of this work was to increase the efficiency of the formation of initial information messages. Using the experimental data in the implementation of the EME working cycles, value of the thermal process velocity accompanying the variable technological modes with the bipolar behavior of the output ordinate were determined. Compared to the heating temperature, the rate of value change with a more noticeable contrast reflected the thermal events in the EME, thus determining the priority of this parameter to increase the efficiency of the measuring device. It has been considered methods of forming an array of initial data using a remote transducer sensor to control the heating temperature of equipment with a modulator. It has been proposed algorithms for the electronic formation of an array of initial values and their sorting according to the “principle of flotation”, when a select variables, belonging to the heating processes or cooling of equipment, is provided. A way and an algorithm for determining the rate of temperature change based on current data using a D-shaper are considered. Experimental studies of the electronic components of the diagnostic device with the D-shaper of the initial data array elements confirmed their physical implementation possibility by hardware and software. The results of data arrays formation, taking into account digital sequences in int format with an error of ± 1 Hz, in contrast to the most controlled parameter – float with an error of ± 0.08 ° C, did not change the properties of information messages, but made it possible to reduce the requirements for a microcalculator or a computing device. The results, obtained using the proposed technical solution, confirmed the possibility of increasing the efficiency of thermal and diagnostic control, contributing to a more accurate identification of possible electric motor malfunctions in the EME. The work presents illustrations confirming the suitability of mathematical descriptions and algorithms for processing the initial data for their practical application in electronic measuring instruments for monitoring and diagnosing malfunctions based on thermal events. Keywords: artificial neural network, remote control, modeling, parameter converter, modulator, transport, traction motor, identification, programming.

scholarly journals Heat transfer in the mold during vertical continuous casting of steel

2018 ◽  
pp. 26-30
Author(s):  
E. I. Marukovich ◽  
E. B. Demchenko
Keyword(s):  
Heat Transfer ◽  
Temperature Regime ◽  
Thermal State ◽  
Effective Means ◽  
Experimental Studies ◽  
Casting Process ◽  
Continuous Casting Of Steel ◽  
Technological Parameters ◽  
Casting Method ◽  
Calculation Technique

The analysis of the performed researches has shown that the offered calculation technique is an effective means of management of formation process in casting. The found dependences and experimental data allow to calculate the specific value of the exactм heat flux in a given range of technological parameters obtained during a series of successful experiments for a particular casting method.Having the results of studies of the temperature regime of the mold during casting of a certain size and profile, it is possible to calculate the thermal state of the mold for the same casting process, but for the production of castings of any other size and profile.Having a certain amount of information on the temperature regime of the mold at different casting methods, you can use the solutions obtained to become the owner of a database containing the necessary information for solving the problems of solidification of the casting. In the subsequent design of equipment and equipment there is no need for additional experimental studies and analysis of the results.

scholarly journals MATHEMATICAL MODELING OF DESTRUCTION OF FIBERGLASS-BASED THERMAL-PROTECTION MATERIAL

2020 ◽  
pp. 71-78
Author(s):  
D.Ya. Barinov ◽  
◽  
P.S. Marakhovskij ◽  
A.V. Zuev ◽  
◽  
...  
Keyword(s):  
Thermal Protection ◽  
Experimental Studies ◽  
Thermophysical Characteristics ◽  
Capsule Type ◽  
Typical Trajectory ◽  
Material Sample ◽  
Heat Shielding ◽  
Physical And Mathematical Models ◽  
The Mathematical Model ◽  
Shielding Material

The paper proposes physical and mathematical models of heat and mass transfer in fiberglass used as a destructive heat-shielding material for capsule type descent vehicles. To provide the mathematical model with the initial data, experimental studies of the thermophysical characteristics of the material and the kinetic parameters of destruction have been carried out. There has been made a simulation of the destruction of a material sample during descent in the Earth's atmosphere along a typical trajectory for various areas of the heat shield; as a result, the dependences of temperatures on the flight time and the depth of the coked layer have been determined.

Analysis of the Influence of Transient State of the Overhead Pipeline Placed in an Open-Air Space on the Accuracy of its Insulation Assessment Based on the Results of Outer Shell Thermovision Diagnostics

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Tadeusz Kruczek
Keyword(s):  
Thermal Insulation ◽  
Thermal Protection ◽  
Thermal State ◽  
Infrared Camera ◽  
Transient State ◽  
Weather Conditions ◽  
Heat Losses ◽  
Energy Accumulation ◽  
Measurement Results

Abstract The proper thermal diagnostics of pipeline insulation is an important problem. The heat losses from the pipelines depend distinctly on the quality of this insulation. Changes in weather conditions cause transient accumulation of energy in the pipeline insulation and may cause difficulties during evaluation of the quality of the pipeline thermal insulation. Generally, the goal of this investigation was to identify the scale of energy accumulation inside thermal insulation. This is important because during the calculation of heat losses from thermal pipelines on the basis of infrared camera temperature measurement results usually a steady thermal state inside the insulation is assumed. In order to determine the distributions of the temperature inside the insulation, the calculations of the temperature changes inside the pipeline insulation for real changeable meteorological conditions with the use of software ansys-fluent and others have been carried out. Both the heat transfer between the inner pipeline tube and outer pipeline shell and energy accumulation inside the pipeline elements were considered. For the pipeline insulation evaluation purpose, different coefficients for the analysis of energy accumulation scale were defined and used. The measurement results of the temperature of inner pipeline tube and outer pipeline shell gathered during the operation of the special experimental rig were used as input data for the aforementioned numerical simulations. In these calculations, they constituted the first (Dirichlet's) boundary condition. The conclusions resulting from this work are useful for specialists involved in the technical evaluation of the thermal protection features of pipelines.

HEAT MONITORING OF HEATING SYSTEM PROTECTION OF A NEW PASSENGER TERMINAL OF THE SAMARA INTERNATIONAL AIRPORT «KURUMOCH»

2015 ◽  
Vol 5 (2) ◽  
pp. 107-112
Author(s):  
Aleksandr Anatol'evich CHULKOV
Keyword(s):  
Heat Transport ◽  
Thermal Insulation ◽  
Thermal State ◽  
Experimental Studies ◽  
Heating System ◽  
Heat Losses ◽  
Experimental Results ◽  
Galvanized Steel ◽  
Transport Systems ◽  
System Protection

The results of experimental studies of thermal state of heat transport lines are viewed. Ready-to-use PU foarm unsulation in polyethylene sheath is taken as thermal insulation of heating system lines under the ground. Readyto- use PU foarm unsulation in sheet galvanized steel sheath is taken as thermal insulation of heating system lines aboveground. Experimental results permit to determine real heat losses of heat transport systems.

Conjugate Heat Transfer and Estimation of Thermal State of Elements of the Thermal Protection Shield Package

2019 ◽  
pp. 44-57
Author(s):  
V.A. Tovstonog
Keyword(s):  
Heat Transfer ◽  
Thermal Deformation ◽  
Conjugate Heat Transfer ◽  
Computational Models ◽  
Thermal Protection ◽  
Thermal State ◽  
Mechanical Contact ◽  
Thermal Insulating ◽  
Temperature State ◽  
Radiation Shields

This article presents the physical and computational models of heat transfer and the high-temperature flow path thermal protection with the use of radiation shields package. The analysis of the thermal insulating ability and temperature state of a multi-element radiation shields package was performed. It is shown that the distribution the temperature of the package elements is uneven, which can cause different thermal deformation of elements, the distortion of the shield, the possibility of mechanical contact of neighboring elements and the deterioration of the heat insulating ability.

scholarly journals Geometrical Parametric Optimisation of A356 Alloy Composite in a Two-Stage Casting Process for Automobile Wheel Covers using Response Surface Methodology

2020 ◽  
Vol 7 (1) ◽  
pp. 457-478 ◽  
Author(s):  
Sunday Oke ◽  
Stephen Chidera Nwafor ◽  
Chris Abiodun Ayanladun
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Regression Models ◽  
Predictive Accuracy ◽  
A356 Alloy ◽  
Casting Process ◽  
Sand Casting ◽  
Phase Method ◽  
Technical Solution ◽  
Two Phase

In recent years, novel products from out–of–use A356 alloy engine components are increasingly produced for the automobile industries. Despite being a promising method the sand casting of these products reveals an inadequately understood cast geometry phenomenon for the process. At present, there is no technical solution to the optimisation of cast geometries for A356 alloy reconfigured into composites through organic matter reinforcements. This paper models and analyse sand casting process product geometries in a two–phase method. It utilises the response surface methodology with data on inputs and outputs to create the regression. Volume and density of the first casting process and the weight loss were evaluated for the various groupings of casting process variables, including length, weight, height, width of product for the first casting, weight, length, breadth of the product for the second casting, and the total weight of organic materials. The input and output associations were established in two models of regression analysis representing the central composite design, CCD. The influences of the cast geometrical variables on the evaluated responses were analysed. Furthermore, the predictive accuracy of the two regression models was evaluated. Results revealed that the applied CCD and the regression models reveals statistical adequacy and are competent to predict accurately.

scholarly journals Application of ANSYS software package for electromagnetic and thermal analysis of the electric motor of the pilger mill drive seamless pipe manufacturing technology

2020 ◽  
pp. 57-66
Author(s):  
B. I. Kosimov ◽  
Keyword(s):  
Thermal Analysis ◽  
Critical Condition ◽  
Permanent Magnets ◽  
Thermal State ◽  
Inertial Mass ◽  
Optimization Methods ◽  
Electrical Equipment ◽  
Design System ◽  
Technical Solution ◽  
Pilger Mill

Currently, the metallurgical production contains a large number of morally and physically outdated electrical equipment that requires modernization. Large capital expenditures are required to replace it. For this reason, it is slow to implement, long-term use for the purpose of payback, and slowly decommissioned. In this regard, the new equipment should be innovative and in many ways ahead of the existing level of development of the industry. The article offers such a solution for the company PJSC «Chelyabinsk pipe rolling plant». To replace the existing collector motor of the pilger mill drive for the manufacture of seamless pipes, which has been operating since 1928 and is in critical condition, a large-size low-speed valve motor with a large built-in inertial mass, having a permanent magnet magnetic system and claw-poles, is proposed to replace the existing collector motor of the pilger mill drive for the manufacturing of seamless pipes, which has been operating since 1928 and is in critical condition. Such a technical solution for drives of this class has not been used in the world. The motor eliminates the existing 120-ton flywheel, improves reliability due to contactless current supply, and reduces operating costs by eliminating excitation losses. The design of the engine allows its assembly without additional technological equipment, which is very important for large engines with permanent magnets. To develop a unique motor, a design system consisting of a synthesis subsystem and an analysis subsystem was created. The synthesis subsystem implements multi-level single-criteria optimization. As a result of its work, the optimal geometry is determined according to the selected criterion. The analysis system confirms the accuracy of the calculation using simplified optimization methods and finally removes technical risks before manufacturing an industrial design. It is based on the Ansys Electronics Desktop and Ansys Icepak systems that are well-developed for CAE electric machines. The analysis has several stages and includes electromagnetic and thermal analysis. The proposed design system is tested on a real project and implemented as a calculation of the magnetic and thermal state with dynamic load in JSC «Russian electric motors»

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