Mathematical modeling of asynchronous squirrel-cage locomotive propulsion engine

2019 ◽  
pp. 41-49
Author(s):  
Otabek Khamidov
Keyword(s):  
Mathematical Model ◽  
Practical Importance ◽  
Transient Behavior ◽  
Equation System ◽  
Phase System ◽  
Model Calculations ◽  
Applied Model ◽  
Squirrel Cage ◽  
Three Phase ◽  
Cage Rotor

Objective: To analyze processes in asynchronous engines in case of failure occurrence in rotor winding. Methods: Mathematical model of asynchronous locomotive propulsion engine with cage rotor (AD) was applied. Model calculations applied for the solution of the differential equation system by means of numerical integration were given. Results: The presented AD mathematical model makes it possible to assess the influence of engine’s parameters and load on transient behavior of motor start, as well as to conduct the research in an asynchronous engine in case of balanced and unbalanced operation modes in a three-phase system of coordinates. The latter allow for an adequate description of physics in stator windings in case of failures of rotor bar windings of AD locomotives. Basic equations for the locomotive propulsion engine stator and rotor of different coordinate systems were presented. A structural computational scheme of a three-phase asynchronous engine with a squirrel-cage rotor was developed, making it possible to calculate AD transients. The mathematical model was implemented with MATLAB Simulink software package. Practical importance: The results obtained by means of locomotive asynchronous engine simulation in case of failures of rotor bar windings, as well as AD twisting moment alteration in time demonstrated the possibility of using such a model in order to detect the specific features of failure occurrence in AD.

Mathematical and Physical Modeling of Three-Phase Gas-Stirred Ladles

2016 ◽  
Vol 1812 ◽  
pp. 29-34
Author(s):  
Juan A. López ◽  
Marco A. Ramírez-Argáez ◽  
Adrián M. Amaro-Villeda ◽  
Carlos González
Keyword(s):  
Mathematical Model ◽  
Physical Model ◽  
Stokes Equations ◽  
Steel Slag ◽  
Flow Patterns ◽  
Navier Stokes ◽  
Steel Ladle ◽  
Phase System ◽  
Navier Stokes Equations ◽  
Three Phase

ABSTRACTA very realistic 1:17 scale physical model of a 140-ton gas-stirred industrial steel ladle was used to evaluate flow patterns measured by Particle Image Velocimetry (PIV), considering a three-phase system (air-water-oil) to simulate the argon-steel-slag system and to quantify the effect of the slag layer on the flow patterns. The flow patterns were evaluated for a single injector located at the center of the ladle bottom with a gas flow rate of 2.85 l/min, with the presence of a slag phase with a thickness of 0.0066 m. The experimental results obtained in this work are in excellent agreement with the trends reported in the literature for these gas-stirred ladles. Additionally, a mathematical model was developed in a 2D gas-stirred ladle considering the three-phase system built in the physical model. The model was based on the Eulerian approach in which the continuity and the Navier Stokes equations are solved for each phase. Therefore, there were three continuity and six Navier-Stokes equations in the system. Additionally, turbulence in the ladle was computed by using the standard k-epsilon turbulent model. The agreement between numerical simulations and experiments was excellent with respect to velocity fields and turbulent structure, which sets the basis for future works on process analysis with the developed mathematical model, since there are only a few three-phase models reported so far in the literature to predict fluid dynamics in gas-stirred steel ladles.

The Role of Dissolved and Nascent Air in Oil-Hydraulic Systems

2000 ◽  
Author(s):  
Hansjoerg Stern
Keyword(s):  
Steady State ◽  
High Performance ◽  
Transient Behavior ◽  
Operating Conditions ◽  
Phase System ◽  
Hydraulic Systems ◽  
Three Phase ◽  
Significant Damage ◽  
Water Hydraulic

Abstract In modern, high performance hydraulic systems the transient behavior of dissolving, dissolved and nascent air under changing dynamic conditions of pressure and temperature is emerging as an increasingly important factor, capable of creating undesirable operating conditions. The paper discusses the question of how to predict the performance of pump inlets and valve discharges, where we have known for some time that cavitation and cavitation-like conditions exist and can cause significant damage. The steady state conditions at which nascent air evolves from saturated air-in-oil solutions is normally one or two orders of magnitude above the vapor pressure of the system fluid. To what extent, therefore, is “cavitation” in these systems an air-oil problem? Or is it an oil-vapor problem that is analogous to cavitation in water hydraulic pumps and turbines? Or have we created the combination of the two, a three-phase system of liquid, gas and vapor?

scholarly journals Aspects of the study of the increase of the energy efficiency in the operation of the induction motors within the ancillary services of a thermoelectric power plant

2020 ◽  
Vol 6 (3) ◽  
pp. 145-156
Author(s):  
Nicolae DIGĂ ◽  
◽  
Valentin NĂVRĂPESCU ◽  
Silvia-Maria DIGĂ ◽  
◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Power Plant ◽  
Thermoelectric Power ◽  
Ancillary Services ◽  
Squirrel Cage ◽  
Design Computing ◽  
Three Phase ◽  
Cage Rotor ◽  
Efficiency Indicators ◽  
Thermoelectric Power Plant

In this paper, the authors systematized and interpreted the results obtained by running their own design computing programs, developed using the facilities offered by the Mathcad mathematical software package combined with facilities offered by appropriate custom chart wizard, provided by Excel. These programs were developed based on the algorithms for calculating the parameters of the equivalent scheme, the electrical balance components and the energy efficiency indicators (efficiency, power factor) for a three-phase induction motor with squirrel cage rotor with deep rectangular bars within the ancillary services of a thermoelectric power plant, using a complete mathematical model for different degrees of loading.

scholarly journals Research of current distribution by phases in asynchronous electric motor with a combined winding

2022 ◽  
Vol 23 (5) ◽  
pp. 150-159
Author(s):  
K. V. Martynov ◽  
L. A. Panteleeva ◽  
D. A. Vasiliev ◽  
E. V. Dresvyannikova
Keyword(s):  
Electric Motor ◽  
Short Circuit ◽  
Asynchronous Motor ◽  
Experimental Sample ◽  
Energy Characteristics ◽  
The Real ◽  
Squirrel Cage ◽  
Three Phase ◽  
Cage Rotor ◽  
Asynchronous Electric Motor

THE PURPOSE. The asynchronous electric motor with a squirrel cage rotor is widely used in the electric driven industry and agricultural machinery. One of the possible ways to improve its energy characteristics is to use a combined 12-zone stator winding instead of the standard 6-zone one. However, in a combined winding with a parallel connection of the «star» and «delta» phases, the phases may not be loaded equally. Therefore, the main purpose of the work under analysis is to study the distribution of currents between the phases of the «star» and «delta» in the asynchronous motor with a combined winding.METHODS. The study was performed on the AIR71V4 engine, rewound onto a combined winding, in which the real ratio of the active resistances of the «delta» and «star» turned out to be 7% less than the theoretical one. The tests were carried out in no-load and short-circuit mode when powered from a three-phase network, as well as in short-circuit mode when one of the line wires is broken.RESULTS. The work gives the values of the currents flowing through the phases of the combined winding. For the experimental sample, the deviation of the obtained currents from the theoretical values is determined. Equations of currents are obtained when one of the linear wires is broken. Schemes for switching on the main contacts of a thermal relay for a motor with a combined winding are proposed.CONCLUSION. The results of the study showed that in an asynchronous motor with a combined winding, in which the real ratio of the active resistances of the «delta» and «star» is less than the theoretical one, the current is not proportionally distributed over the phases. The most preferred circuit for switching on a thermal relay is one in which its main contacts are connected to the «delta» phases, and the thermal relay must be three-pole.

scholarly journals Vector Simulation of Deep-Bar Induction Motor

2021 ◽  
Vol 2096 (1) ◽  
pp. 012100
Author(s):  
B A Korobeynikov ◽  
A M Oppakhodzhaev ◽  
D I Sidorov
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Coordinate System ◽  
Induction Motor ◽  
Electric Circuit ◽  
Vector Model ◽  
New Approach ◽  
Squirrel Cage ◽  
Cage Rotor ◽  
Motor Model

Abstract The paper considers a mathematical model of a deep-bar induction motor with a squirrel-cage rotor in the generalized vector coordinates. The transition from the induction motor mathematical in the phase coordinate system to the motor’s vector model in the generalized vector coordinates is shown, which allows obtaining a simpler induction motor model applicable for the analysis of steady-state and transient modes. A new approach to simulating a motor in the form of an electric circuit is not only inductances but also complex resistances interconnected.

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