scholarly journals Starting generator driving torque modeling in the studies of synchronous starting of synchronous machines

2002 ◽  
Vol 15 (3) ◽  
pp. 399-408
Author(s):  
Zoran Stajic ◽  
Dragan Petrovic ◽  
Dusan Arnautovic
Keyword(s):  
Mathematical Model ◽  
Linear Function ◽  
Polynomial Approximation ◽  
System Model ◽  
Synchronous Machines ◽  
Model Function ◽  
Detailed Model ◽  
Pumped Storage ◽  
Driving Torque ◽  
Time Linear

The paper deals with significance of the starting generator (SG) driving torque modeling in the studies of synchronous starting of synchronous machines (SSSM). The detailed mathematical model of SSSM in reversible pumped storage plant (RPSP) "Bajina Basta" is derived. Because it is very difficult to include the detailed model of the SG turbine in the system model, function of SG driving torque is modeled approximately. The most frequent case in SSSM studies is its approximation with a time linear function, until it reaches the value that should provide rotating of both machine rotors with synchronous velocities, which is also used in the paper Afterwards, three different cases are considered: constant, linear and polynomial approximation in terms of SG rotor velocity. Numerical results obtained by applying developed models to a particular case of synchronous starting are compared with the corresponding experimental results. In this way, it is shown that the application of the most frequently used SG driving torque modeling leads to the erroneous results. The advantages of the polynomial approximation suggested in the paper and its validity is demonstrated.

A mathematical model of the cool-flame oxidation of acetaldehyde

1971 ◽  
Vol 322 (1550) ◽  
pp. 377-403 ◽  
Keyword(s):  
Mathematical Model ◽  
Negative Temperature ◽  
Isothermal Oxidation ◽  
Limited Range ◽  
Detailed Model ◽  
Cool Flame ◽  
Induction Periods ◽  
Cool Flames ◽  
Satisfactory Account ◽  
Flame Oxidation

A detailed mathematical model of the non-isothermal oxidation of acetaldehyde has been found to give a realistic simulation of (i) single and multiple cool flames, their limits, amplitudes and induction periods; (ii) two-stage ignition; and (iii) the negative temperature coefficient for the maximum rate of slow combustion. A simplified form of the model, valid over a limited range of conditions, has been subjected to mathematical analysis to provide interpretations of the effects simulated by the detailed model. It is concluded that cool flames are thermokinetic effects often, but not exclusively, of an oscillatory nature, and that a satisfactory account of cool-flame phenomena must necessarily take reactant consumption into account.

scholarly journals A Multiphase Flow in the Antroduodenal Portion of the Gastrointestinal Tract: A Mathematical Model

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
P. V. Trusov ◽  
N. V. Zaitseva ◽  
M. R. Kamaltdinov
Keyword(s):  
Mathematical Model ◽  
Gastrointestinal Tract ◽  
Multiphase Flow ◽  
Human Body ◽  
Digestive System ◽  
System Model ◽  
Food Density ◽  
Secretory Function ◽  
Functional Disorders ◽  
Food Particles

A group of authors has developed a multilevel mathematical model that focuses on functional disorders in a human body associated with various chemical, physical, social, and other factors. At this point, the researchers have come up with structure, basic definitions and concepts of a mathematical model at the “macrolevel” that allow describing processes in a human body as a whole. Currently we are working at the “mesolevel” of organs and systems. Due to complexity of the tasks, this paper deals with only one meso-fragment of a digestive system model. It describes some aspects related to modeling multiphase flow in the antroduodenal portion of the gastrointestinal tract. Biochemical reactions, dissolution of food particles, and motor, secretory, and absorbing functions of the tract are taken into consideration. The paper outlines some results concerning influence of secretory function disorders on food dissolution rate and tract contents acidity. The effect which food density has on inflow of food masses from a stomach to a bowel is analyzed. We assume that the future development of the model will include digestive enzymes and related reactions of lipolysis, proteolysis, and carbohydrates breakdown.

scholarly journals Applied Optimization and Approximation

2014 ◽  
Vol 3 (4) ◽  
pp. 37-48
Author(s):  
Octav Olteanu
Keyword(s):  
Optimal Control ◽  
Cost Function ◽  
Linear Function ◽  
Polynomial Approximation ◽  
Moment Problem ◽  
Quadratic Forms ◽  
Two Dimensional ◽  
Several Variables ◽  
Applied Optimization ◽  
The Moment

The present work deals with optimization in kinematics, generalizing previous results of the author. A second theme is maximizing the constrained gain linear function and minimizing the constrained cost function. Elementary notions of optimal control are considered as well. Finally, polynomial approximation results on unbounded subsets in several variables are applied to the moment problem. The existence of the solution of a two dimensional moment problem is characterized in terms of quadratic forms.

Extended validation of a ground-based three-axis spacecraft simulator model

2020 ◽  
pp. 095441002093896
Author(s):  
H Sh Ousaloo ◽  
Gh Sharifi ◽  
B Akbarinia
Keyword(s):  
Mathematical Model ◽  
Attitude Control ◽  
Aerodynamic Drag ◽  
Center Of Mass ◽  
Model Development ◽  
Optimization Method ◽  
Experimental Results ◽  
Spacecraft Dynamics ◽  
Detailed Model ◽  
Mass Properties

The ground-based spacecraft dynamics simulator plays an important role in the implementation and validation of attitude control scenarios before a mission. The development of a comprehensive mathematical model of the platform is one of the indispensable and challenging steps during the control design process. A precise mathematical model should include mass properties, disturbances forces, mathematical models of actuators and uncertainties. This paper presents an approach for synthesizing a set of trajectories scenarios to estimate the platform inertia tensor, center of mass and aerodynamic drag coefficients. Reaction wheel drag torque is also estimated for having better performance. In order to verify the estimation techniques, a dynamics model of the satellite simulator using MATLAB software was developed, and the problem reduces to a parameter estimation problem to match the experimental results obtained from the simulator using a classical Lenevnberg-Marquardt optimization method. The process of parameter identification and mathematical model development has implemented on a three-axis spherical satellite simulator using air bearing, and several experiments are performed to validate the results. For validation of the simulator model, the model and experimental results must be carefully matched. The experimental results demonstrate that step-by-step implementation of this scenario leads to a detailed model of the platform which can be employed to design and develop control algorithms.

scholarly journals A MODEL FOR BREACH GROWTH IN A DIKE-BURST

1988 ◽  
Vol 1 (21) ◽  
pp. 140 ◽  
Author(s):  
Paul J. Visser
Keyword(s):  
Mathematical Model ◽  
The Netherlands ◽  
Laboratory Experiments ◽  
Suspended Load ◽  
Experimental Results ◽  
Sand Transport ◽  
Model Predictions ◽  
Pumped Storage

A mathematical model for sand-dike breach erosion is presented. The heart of the model is a modified Bagnold (1963) energetics—based sand transport conception combined with a simplified Galappatti and Vreugdenhil (1985) pick up mechanism for the suspended load. The model has been tested to three laboratory experiments. The agreement between model predictions and experimental results is surprisingly good. Prototype calculations are presented for the 73 m high sand—dike of a proposed pumped—storage plant in the Netherlands.

The Universal Mathematical Model of Excitation System of Synchronous Machines

2015 ◽  
Vol 792 ◽  
pp. 167-173
Author(s):  
Nikolay Ruban ◽  
Yuri Borovikov ◽  
Venera Sulaymanova
Keyword(s):  
Mathematical Model ◽  
Synchronous Machines ◽  
Excitation System ◽  
The Mathematical Model

The article presents the results of the synthesis of universal mathematical model of the excitation system of synchronous machines that can adequately reproduce a variety of excitation systems with different regulation laws. The information about the practical verification of the mathematical model is given in the paper.

Fault Diagnosis for Suspension Signal of Maglev Vehicle Based on Mathematical Model

2012 ◽  
Vol 190-191 ◽  
pp. 987-992 ◽  
Author(s):  
Ying Pu Cui ◽  
Long Hua She ◽  
Xiao Long Li ◽  
A Ming Hao
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Fault Diagnosis ◽  
System Model ◽  
Maglev Vehicle ◽  
Suspension Control ◽  
Diagnosis Method ◽  
Real Value ◽  
Control System Model

Firstly, build the suspension-control-system model under the condition of elastic guideway, and design the controller. Secondly, design the Kalman forecaster based on model, and diagnose the fault by comparing forecasted value with real value. Finally, verify the effectiveness of this fault diagnosis method for suspension signal by simulation.

scholarly journals Mathematical model of pantograph cooperation with two degrees of freedom with a catenary system

2019 ◽  
Vol 294 ◽  
pp. 05005
Author(s):  
Marek Kaniewski ◽  
Michał Cichoński
Keyword(s):  
Mathematical Model ◽  
Discrete Model ◽  
Degrees Of Freedom ◽  
Variable Stiffness ◽  
System Model ◽  
Dynamic State ◽  
Rolling Stock ◽  
Two Degrees Of Freedom ◽  
Technical Specifications ◽  
Catenary System

The authors present a method of modeling pantograph cooperation with a catenary system by means of a computer program based on a pantograph discrete model with two degrees of freedom and a catenary system model as a focused mass that in the dynamic state has variable stiffness along the span. After performing the appropriate tests, the validation was carried out according to the proposed method in the PN EN 50318:2019-02 standard required in the Technical Specifications for the interoperability of the subsystem “Energy” and “Rolling stock -locomotives and passenger rolling stock” of the trans-European rail system in Europe.

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