Mathematical Model for Thermostatic Expansion Valve

2000 ◽  
Author(s):  
Yiwu Ding ◽  
Dereje Agonafer ◽  
Roger Schmidt
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Simple Model ◽  
Refrigeration System ◽  
Mutual Dependence ◽  
Control Functions ◽  
Steady State Operation ◽  
Expansion Valve ◽  
And Control ◽  
The Mathematical Model

Abstract A methodology to generate the mathematical model to simulate the steady-state operation of the thermostatic expansion valves is described. Such a model is necessary in understanding the operation of a refrigeration system used in cooling electronics. The model treats the mutual dependence between the valve’s throttling and control functions, and requires a few experimentally determined parameters. Specifically, the characteristic of the valve changes with the evaporating temperature, and a simple model to represent this influence on the valve is suggested.

A prey–predator model and control of a nematodes pest using control in banana: Mathematical modeling and qualitative analysis

2021 ◽  
pp. 2150089
Author(s):  
Sudhakar Yadav ◽  
Vivek Kumar
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Local Stability ◽  
Detection Method ◽  
Initial Release ◽  
Pest Detection ◽  
Predator Model ◽  
And Control ◽  
The Mathematical Model ◽  
Theoretical Results

This study develops a mathematical model for describing the dynamics of the banana-nematodes and its pest detection method to help banana farmers. Two criteria: the mathematical model and the type of nematodes pest control system are discussed. The sensitivity analysis, local stability, global stability, and the dynamic behavior of the mathematical model are performed. Further, we also develop and discuss the optimal control mathematical model. This mathematical model represents various modes of management, including the initial release of infected predators as well as the destroying of nematodes. The theoretical results are shown and verified by numerical simulations.

scholarly journals New “Full-Bridge Buck Inverter–DC Motor” System: Steady-State and Dynamic Analysis and Experimental Validation

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1216 ◽  
Author(s):  
Eduardo Hernández-Márquez ◽  
Carlos Alejandro Avila-Rea ◽  
José Rafael García-Sánchez ◽  
Ramón Silva-Ortigoza ◽  
Magdalena Marciano-Melchor ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Motor System ◽  
Circuit Simulation ◽  
Dc Motor ◽  
Matlab Simulink ◽  
Duty Cycles ◽  
System Variables ◽  
The Mathematical Model ◽  
Steady State Stability

A mathematical model of a new “full-bridge Buck inverter–DC motor” system is developed and experimentally validated. First, using circuit theory and the mathematical model of a DC motor, the dynamic behavior of the system under study is deduced. Later, the steady-state, stability, controllability, and flatness properties of the deduced model are described. The flatness property, associated with the mathematical model, is then exploited so that all system variables and the input can be differentially parameterized in terms of the flat output, which is determined by the angular velocity. Then, when a desired trajectory is proposed for the flat output, the input signal is calculated offline and is introduced into the system. In consequence, the validation of the mathematical model for constant and time-varying duty cycles is possible. Such a validation of this mathematical model is tackled from two directions: (1) by circuit simulation through the SimPowerSystems toolbox of Matlab-Simulink and (2) via a prototype of the system built by using Matlab-Simulink and a DS1104 board. The good similarities between the circuit simulation and the experimental results allow satisfactorily validating the mathematical model.

Study of Topology and Control Strategy of the Bidirectional Energy Storage Converter Based on Three-Level

2013 ◽  
Vol 397-400 ◽  
pp. 1169-1173
Author(s):  
Hong Wei Tang ◽  
Xi Kun Chen ◽  
Yan Xia Gao
Keyword(s):  
Mathematical Model ◽  
Energy Storage ◽  
Control Strategy ◽  
Lithium Battery ◽  
Decoupling Control ◽  
Midpoint Potential ◽  
Simulation Results ◽  
And Control ◽  
The Mathematical Model ◽  
Battery Module

To adapt to the requirements of the charging and discharging of the lithium battery, the paper presents a three-level based bidirectional energy storage converter topology.It has strong adaptability and can manage the charge and discharge of multi-series and parallel battery module. The mathematical model of the converter is analyzed, and the two operation modes of the converter control strategy are studied; Analysis the feed-forward decoupling control of three-level rectifier, and the variable scale factor is used to control midpoint potential. The simulation results demonstrate the feasibility of the design.

A Control System on Soil Temperature

2014 ◽  
Vol 599-601 ◽  
pp. 673-679
Author(s):  
Shi Guo Chen ◽  
Li Hua Hu ◽  
Dong Sheng Wu ◽  
Xue Yong Chen
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Soil Temperature ◽  
Control Algorithm ◽  
Soil Ecology ◽  
Control Soil ◽  
Pid Algorithm ◽  
And Control ◽  
The Mathematical Model

The soil’s temperature plays an important role of soil ecology research. In order to gain and control soil’ temperature. A control system is proposed for soil’s temperature. And a new control algorithm which is based on the PID algorithm is designed in the control system to handle the complex change of the soil’s temperature. It does not need to know the mathematical model of soil’s temperature. At last, the control result is analyzed in this paper. The result shows that the soil’s temperature is controlled ideal by this control system which is accurate to 0.5°C.

The Effect of Leakage on Railroad Brake Pipe Steady State Behavior

1988 ◽  
Vol 110 (3) ◽  
pp. 329-335 ◽  
Author(s):  
K. Abdol-Hamid ◽  
D. E. Limbert ◽  
G. A. Chapman
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Transmission Lines ◽  
Computation Time ◽  
State Behavior ◽  
Implicit Finite Difference Scheme ◽  
Inlet Flow Rate ◽  
Model Equations ◽  
The Mathematical Model ◽  
Steady State Behavior

A mathematical model for pneumatic transmission lines containing leakage is developed. This model is used to show the effect of leakage size and distribution on the steady state behavior of the brake pipe on a train brake system. The model equations are solved using the implicit finite difference scheme without neglecting any terms. The model is presented in a nonlinear continuous network form, consisting of N sections. Each of the network sections represents one car and may contain one leakage. A computer program was developed to solve the model equations. This program is capable of simulating a train with cars of various lengths and takes a minimum amount of computation time as compared with previous methods. Through analysis and experimentation, the authors have demonstrated that pressure gradient and inlet flow rate are very sensitive to leakage locations as compared with leakage size. The results, generated by the mathematical model, are compared with the experimental data of two different brake pipe set-ups having different dimensions.

scholarly journals Mass transfer during electrodeposition of metals at a periodically changing rate

1999 ◽  
Vol 64 (5-6) ◽  
pp. 317-340 ◽  
Author(s):  
Miodrag Maksimovic ◽  
Konstantin Popov
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Steady State ◽  
Layer 4 ◽  
Millisecond Range ◽  
The Mathematical Model ◽  
Pulsating Current ◽  
Pulsating Overpotential ◽  
Changing Rate ◽  
Electrodeposition Of Metals

1. Introduction 2. Mass transfer in the steady state periodic condition 2.1. Reversing current 2.2. Pulsating current 2.3. Alternating current superimposed on direct current 3. The influence of the charge and discharge of the electrical double layer 4. The validity of the mathematical model 4.1. Reversing current in the millisecond range 4.2. Reversing current in the second range 4.3. Pulsating current 4.4. Pulsating overpotential 5. Conclusion

scholarly journals Analisis Kontrol Optimal Pada Model Matematika Penyebaran Pengguna Narkoba Dengan Faktor Edukasi

2020 ◽  
Vol 17 (2) ◽  
pp. 238-248
Author(s):  
Resmawan ◽  
M Eka ◽  
Nurwan ◽  
N Achmad
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Optimal Control ◽  
Drug Users ◽  
Minimum Principle ◽  
Runge Kutta Method ◽  
Runge Kutta ◽  
Model Drug ◽  
And Control ◽  
The Mathematical Model

ABSTRACT This paper discusses the mathematical model of drug users with education. Optimal control theory was used on this model with education as a control to achieve the goal of minimizing the number of drug users. The optimal control problem was analyzed using Pontryagin’s minimum principle and performed numerical simulation by using a 4th-order Runge-Kutta method. Based on the numerical simulation, there was a change in the number in each population which caused the population with education to increase, and control with education resulted in the reduced number of drug users. Keywords: Optimal control; mathematical model; drug users; education   ABSTRAK Artikel ini membahas tentang model matematika penyebaran pengguna narkoba dengan faktor edukasi. Teori kontrol optimal diterapkan pada model ini dengan pemberian kontrol berupa edukasi dengan tujuan untuk meminimumkan jumlah pengguna narkoba. Kontrol optimal dianalisis menggunakan Prinsip Minimum Pontryagin dan dilakukan simulasi numerik dengan menggunakan metode Runge-Kutta orde 4. Berdasarkan simulasi diperoleh bahwa terjadi perubahan jumlah di tiap populasi dan mengakibatkan jumlah populasi dengan edukasi bertambah, serta pemberian kontrol dengan edukasi mengakibatkan jumlah pengguna narkoba berkurang. Kata kunci       : Kontrol optimal; model matematika; pengguna narkoba; edukasi

scholarly journals On the global attractors in one mathematical model of antiviral immunity

2020 ◽  
Author(s):  
Alexei Tsygvintsev
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Immune System ◽  
Asymptotic Stability ◽  
Global Asymptotic Stability ◽  
Antiviral Immunity ◽  
Global Attractors ◽  
Viral Pathogens ◽  
Basic Reproductive Ratio ◽  
The Mathematical Model

AbstractWe consider the mathematical model introduced by Batholdy et al. [1] describing the interaction between viral pathogens and immune system. We prove the global asymptotic stability of the infection steady-state if the basic reproductive ratio R0 is greater than unity. That solves the conjecture announced in [7].

Modeling and Simulation of Educational Linear Motion Module

2009 ◽  
Author(s):  
Dian-sheng Chen ◽  
Yu-xin Chen ◽  
Tian-miao Wang
Keyword(s):  
Mathematical Model ◽  
Dynamic Performance ◽  
Linear Motion ◽  
Motion Model ◽  
Load Case ◽  
Know How ◽  
Working Principle ◽  
And Control ◽  
The Mathematical Model ◽  
Control Accuracy

In order to let the student understand the linear motion module’ principles and know how to improve the dynamic performance and control accuracy, a mathematical model is established based on the analysis of the composition and working principle of linear motion module. On the load and unload conditions, we simulate and analyze the system respectively. In the load case, PID parameters are obtained after the PID regulation. The correction of establishing the mathematical model and simulating the system are verified so that the linear motion model’ precision is effectively enhanced.

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