scholarly journals Mathematical model of electrical system including transformer and electrical drives based on induction motors and synchronous motors

2019 ◽  
Vol 84 ◽  
pp. 02001
Author(s):  
Marek Lis ◽  
Andriy Chaban
Keyword(s):  
Mathematical Model ◽  
Power Transmission ◽  
Induction Motors ◽  
Power Transformer ◽  
Electrical System ◽  
State Equations ◽  
Synchronous Motors ◽  
Electrical Drives ◽  
The Mathematical Model ◽  
Modelling Methods

On the basis of interdisciplinary modelling methods the mathematical model of the electromechanical system, including power transformer, induction motors and synchronous motors, is formulated and presented in the paper. The motors are joined with the driven objects through a mechanical power transmission system. In addition, the transformer is loaded by nonlinear circuit RL. Differential state equations of the studied system are given as the Cauchy’s formulas. Numerical simulations of the system operation have been made for the selected cases. The results of computer simulation are presented in a graphic form.

Analysis of mathematical models of transmission lines.

2020 ◽  
Vol 23 (2) ◽  
pp. 16-19
Author(s):  
G. SHEINA ◽  
Keyword(s):  
Mathematical Model ◽  
Power Systems ◽  
Transmission Lines ◽  
Power Supply ◽  
Power Supply System ◽  
Power Transmission ◽  
Supply System ◽  
Power Lines ◽  
Power Transmission Lines ◽  
The Mathematical Model

This paper investigates a mathematical model of one elements of the power supply system - power transmission lines. The type of models depends on the initial simplifications, which in turn are determined by the complexity of the physics of processes. The task of improving the accuracy of modeling of emergency processes in the power system is due to the significant complexity of modern power systems and their equipment, high-speed relay protection, automation of emergency management and the introduction of higher-speed switching equipment. One of the reasons for a significant number of serious emergencies in the system is the lack of complete and reliable information for modeling modes in the design and operation of power systems. The development of a mathematical model of a three-phase power line, which provides adequate reflection of both normal and emergency processes, is relevant. The advanced mathematical model of power transmission lines allows to investigate various operational modes of electric networks. The improved mathematical model of the power transmission line reflects all the features of physical processes at state modes and transient process and provides sufficient accuracy of the results. The type of mathematical model of power transmission lines depends on the accepted simplifications, depending on the task of research. The purpose of this work is to analyze the mathematical model of the power transmission line to study the modes of operation of the power supply system, with the possibility of its application to take into account all the design features of overhead and cable power lines. The mathematical model of the power line for the study of the modes of operation of the power supply system is analyzed. It is used to take into account the design features of overhead and cable power lines, skin effect.

The Calculation Method of Lock-Up Clutch Friction Work

2013 ◽  
Vol 475-476 ◽  
pp. 1375-1381
Author(s):  
Jian Rui Duan ◽  
Jin Yao ◽  
Hua Li
Keyword(s):  
Mathematical Model ◽  
Dynamic Model ◽  
Calculation Method ◽  
Power Transmission ◽  
Torque Converter ◽  
Improved Method ◽  
Matlab Simulink ◽  
Hydraulic Torque Converter ◽  
The Mathematical Model

In order to calculate the friction work of lock-up clutch, which come from the lock-up process of hydraulic torque converter, this article established a simplified dynamic model of the engine and hydraulic torque converter , according to the route of power transmission and the rule of moment balance. And then the mathematical model of the lock-up process was deduced. This article reached a calculation method of lock-up clutch friction work by the mathematical model , and did some further simplified. Meanwhile, the lock-up process was simulated by Matlab/Simulink. By analyzing the simulatin resultthe computed result of machinery bookthe computed result of the improved method, the correctness of the improved method was verified.

Study on Stability of Hydroelectric Generating Set Influenced by the Governor Parameters under Isolated Grid

2014 ◽  
Vol 875-877 ◽  
pp. 1799-1803
Author(s):  
Qing Song Huang ◽  
Xiao Juan Zhai ◽  
Yuan Zheng ◽  
Guang Wen Xu ◽  
Hao Wang
Keyword(s):  
Mathematical Model ◽  
Transition Process ◽  
Hydropower Station ◽  
Electrical System ◽  
Generating Set ◽  
Small Fluctuation ◽  
The Mathematical Model

In order to study on stability of hydroelectric generating set under isolated grid, taking hydraulic, mechanical, and electrical system into consideration to build the mathematical model. This paper has researched on the main governor parameters sensitivity in the small fluctuations transition process of complex hydropower station under isolated grid. According to the simulated results, KP or KI increases, or KD decreases appropriately, governor quality of small fluctuation transition process will be better. The influence caused by KD is the most obvious of the three.

scholarly journals Optimal design of the rotor geometry of line-start permanent magnet synchronous motor using the bat algorithm

Open Physics ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 965-970 ◽  
Author(s):  
Łukasz Knypiński
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
Permanent Magnet Synchronous Motor ◽  
Bat Algorithm ◽  
Synchronous Motor ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors ◽  
Basic Language ◽  
Visual Basic Language ◽  
The Mathematical Model

AbstractIn this paper an algorithm for the optimization of excitation system of line-start permanent magnet synchronous motors will be presented. For the basis of this algorithm, software was developed in the Borland Delphi environment. The software consists of two independent modules: an optimization solver, and a module including the mathematical model of a synchronous motor with a self-start ability. The optimization module contains the bat algorithm procedure. The mathematical model of the motor has been developed in an Ansys Maxwell environment. In order to determine the functional parameters of the motor, additional scripts in Visual Basic language were developed. Selected results of the optimization calculation are presented and compared with results for the particle swarm optimization algorithm.

scholarly journals Experimental studies of the method of mutual load of induction motors

2020 ◽  
pp. 44-49
Author(s):  
V. V. Kharlamov ◽  
◽  
D. I. Popov ◽  
P. S. Sokolov ◽  
L. E. Serkova ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Experimental Data ◽  
Mathematical Model ◽  
Induction Motors ◽  
Experimental Studies ◽  
Electromechanical System ◽  
Experimental Equipment ◽  
Frequency Converters ◽  
Parameter Values ◽  
The Mathematical Model

The article presents the results of comparison of experimental studies and mathematical modeling of the stand for testing induction motors by the method of mutual load. A detailed description of the composition of the experimental equipment, which is based on a pair of frequency converters and connected to them a pair of engines of the АИС71В4 type with a nominal power of 0,75 kW, the shafts of which are rigidly connected by a coupling. The mathematical model of the electromechanical system used in the calculations is presented, and its main assumptions are listed. A table of parameter values and graphs obtained from calculated and experimental data are presented. The analysis of the obtained data shows the possibility of using the considered mathematical model with the existing assumptions in the design of electrical complexes intended for testing induction motors by the method of mutual load

scholarly journals State equations in the mathematical model of dynamic behaviour of multihull floating unit

2010 ◽  
Vol 17 (1) ◽  
pp. 33-38
Author(s):  
Agnieszka Królicka
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Dynamic Behaviour ◽  
Physical Models ◽  
Head Wave ◽  
Sea Waves ◽  
State Equations ◽  
Initial Stage ◽  
Mutual Relations ◽  
The Mathematical Model

State equations in the mathematical model of dynamic behaviour of multihull floating unit This paper concerns dynamic behaviour of multihull floating unit of catamaran type exposed to excitations due to irregular sea waves. Dynamic analysis of multihull floating unit necessitates, in its initial stage, to determine physical model of the unit and next to assume an identified mathematical model. Correctly elaborated physical models should contain information on the basis of which a mathematical model could be built. Mathematical models describe mutual relations between crucial quantities which characterize a given system in time domain. The dynamic analysis of multihull unit was performed under assumption that the unit's model has been linear and exposed to action of irregular sea waves. Mathematical model of such dynamic system is represented by state equations. The formulated equations take into account encounter of head wave which generates symmetrical motions of the unit, i.e. surge, heave and pitch. For solving the equations the following three wave spectra were taken into consideration: - ISSC (International Ship Structures Congress) spectrum - Pierson-Moskowitz spectrum - Paszkiewicz spectrum.

Analysis of the synchronous motors behavior in the transients for backup power supply. Purpose.

2020 ◽  
Vol 23 (2) ◽  
pp. 28-37
Author(s):  
V. F. SYVOKOBYLENKO ◽  
◽  
V.A. LYSENKO ◽  
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Power Supply ◽  
Optimization Methods ◽  
Synchronous Motor ◽  
Magnetic Core ◽  
Synchronous Motors ◽  
Salient Pole ◽  
Passport Data ◽  
The Mathematical Model

Simulation of transient and steady state modes of synchronous motors for the analysis of switching to backup power using mathematical model. Method. The methods of linear algebra, numerical optimization methods, methods of modeling and analysis of established and transient modes are used. Results. The mathematical model of the salient pole rotor and non-salient or cylindrical pole rotor synchronous motor is presented, which is presented in the form of a alternate scheme, which allows to take into account the effect of displacement of current and saturation of the non-salient pole rotor motor's magnetic core. A method for determining the parameters of the synchronous motor based on passport data is proposed, which allows to improve the accuracy of modeling in steady state and transient modes. The mathematical model is reduced to a three-phase coordinate system a, b, c of the stator winding. The rotor windings are modeled in the coordinates d, q. The results of mathematical modeling allow us to determine the magnitude of the shock currents and mechanical moments of the synchronous motor. It is shown that non-synchronous switching on of the synchronous motor, which occurs in case of automatic transfer switch, can lead to engine damage. Shock currents can also be dangerous to other power supply equipment. Thus, synchronous motors, if transfer switch is used, require synchronization before being connected to the network. Scientific novelty. The mathematical model of the synchronous motor was improved taking into account the displacement of current and saturation of the magnetic conduit, the method of determining the parameters of the mathematical model based on the passport data of the engine was improved, which allowed to increase the accuracy of the simulation and the reliability of the simulation results. The modes of power transfer switch are simulated and the values of shock current and shock mechanical moment of the engine are obtained. Practical meaning. The mathematical model of the synchronous motor allows to analyze the behavior of synchronous motors in interaction in the power supply system and to identify the dangerous states of synchronous motors that may occur during the transfer switching. The proposed model improves the accuracy of determination of the limits of dangerous states and improves the reliability of synchronous motors and power supply systems.

An Enhanced Mathematical Model for Investigating the Dynamic Loading of a Slewing Crane

2006 ◽  
Vol 220 (4) ◽  
pp. 421-433 ◽  
Author(s):  
B Jerman
Keyword(s):  
Mathematical Model ◽  
Dynamic Loading ◽  
Power Transmission ◽  
Steel Structure ◽  
Main Bearing ◽  
Air Resistance ◽  
Spatial Oscillation ◽  
Comparison Of The Results ◽  
The Mathematical Model

A fatigue analysis of a structure is nowadays a common part of the design process. One of the fundamental pieces of information for ensuring the high quality of the analysis is details of the dynamic loading of the structure. This information can be provided by means of a simulation using an appropriate mathematical model. In this article, a new mathematical model of a slewing crane is presented on the basis of the experiences gained with a previously developed model. Only the slewing motion that produces the spatial oscillation of the payload is considered, as this motion has received less attention than the translation of the suspension point. The mathematical model takes into account the non-linear nature of the swinging motion for large angles and the non-linearity of the power transmission to ensure sufficient accuracy. The structure's elasticity and damping, the friction in the main bearing, and the air resistance were also taken into account. The angles of swinging of the payload and the dynamic forces acting on the steel structure of the crane during payload transport were obtained. Measurements on an actual model of a crane were carried out for the purpose of confirmation of the mathematical model. The comparison of the results was executed and a good greement between the predicted and the measured values was observed.

scholarly journals Mathematical model of a drive system with synchronous motors and vertical pumps

2019 ◽  
Vol 84 ◽  
pp. 02015
Author(s):  
Andrzej Szafraniec
Keyword(s):  
Mathematical Model ◽  
Computer Simulation ◽  
Differential Equations ◽  
Power Transformer ◽  
Nonlinear Differential Equations ◽  
Drive System ◽  
Dynamic State ◽  
Electrical Load ◽  
Synchronous Motors ◽  
Electromechanical Transients

The paper presents a mathematical model of an electrical load node consisting of a power transformer and synchronous motors which rotate vertical pumps using non-rigid transmission. Modified principle of Hamilton–Ostrogradsky served as the basis for construction of the model. Using the developed mathematical model of the node, electromechanical transients in the object are studied. The resultant system of dynamic state nonlinear differential equations is introduced in the normal Cauchy’s form. Computer simulation findings are displayed by means of figures; they are under ongoing analysis.

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