• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 41
  • 40
  • 8
  • 5
  • 5
  • 5
  • 3
  • 3
  • 3
  • 2
  • 1
  • Tagged with
  • 121
  • 121
  • 30
  • 26
  • 26
  • 26
  • 18
  • 14
  • 12
  • 12
  • 12
  • 11
  • 11
  • 11
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Modelování silové sítě pro datovou komunikaci / Modelling of Power Line Communication for data transmission

Kadlček, Václav January 2009 (has links)
Thesis deals with problems PLC (Power Line Communication) communication. It is aimed at drawing up a suitable model for testing power network PLC communication. The reader is aware of at the beginning of work with the basic principles of PLC systems, distribution and use in communication networks. Another part of the work deals with different types of interference, which occur in power networks and ways to defend against such interference. For example, an appropriate choice of modulation and coding relevant. As a source of interference in the proposed model is used AWGN channel (Additive White Gaussian Noise). Conclusion of work is dedicated to design and build a model for PLC communication. There are three models designed with different OFDM technology. Models therefore vary between different levels of key mapping in OFDM (QPSK, 16-QAM, 64-QAM). It made a detailed description of a set of blocks that were used to build models. The behavior and functionality of the proposed models for broadband PLC communication was verified in the simulation program Matlab Simulink. Finally, it is shown the comparison and evaluation of results of each modulation.
2

Microgrid Modeling, Planning and Operation

Su, Wencong 10 December 2009 (has links)
As distributed generations and renewable energy are becoming the fastest growing segment of the energy industry, the technical issues and environmental impacts have to be studied and understood. The large number of small-scale Microgrid components with their own characteristics is a big challenge for Microgrid modeling, simulation, planning and operation. The major goal of this thesis is to build a library of various Microgrid components. First of all, the thesis is going to present a detailed description of Microgrid models with moderate complexity. Next, it will present the modeling of loads, utility grid and transmission lines. Then, the paper will discuss the distributed generation models that have been developed in Matlab/Simulink including Diesel Engine, Fuel Cell, Micro Gas Turbine, Wind Turbine, Photovoltaic Cell, along with the detailed modeling of short-term storage (Battery, Pumped Hydro Storage, Flywheel, and Supercapacitor). In addition to steady-state study, the thesis will also discuss the hybrid sample systems that are built to investigate their transient responses. To enhance the simulation performance, some improvements on modeling and simulation will be introduced as well. To accommodate the high demand of renewable energy and the environment policy, the planning and operation the of Micro-source generators has been studied using HOMER. Simulation results show a case study of an optimal microgrid configuration on Ontario area in Canada. Sensitivity variables are specified to examine the effect of uncertainties, especially in a long-term planning. Also, demand side management plays an important role in the operation of Microgrid. Based on raw data, case studies are carried out to investigate and validate the demand response methods. Finally, the philosophy for Microgrid protection, especially Time-delay overcurrent protection, will be briefly introduced in both gird-connected and islanding modes. / Master of Science
3

Determinação das freqüências naturais e modos de vibrar de um veículo de dois eixos através de um programa computacional em Matlab-Simulink / Determination of the natural frequencies and ways to vibrate of a vehicle of two axles through a computational program in MatLab-Simulink

Ferreira, Hudson Tadeu 10 December 2003 (has links)
Este trabalho obtém as frequências naturais e seus respectivos modos de vibrar da massa suspensa e não suspensa de um veículo comercial através de um programa computacional desenvolvido em MatLab Simulink. As rodas do veículo são excitadas no modelo teórico com sinais harmônicos de frequência continuamente variável de 0 a 40 Hz e de 0 a 4 Hz, faixas que contém as frequências naturais da massa suspensa e não suspensa. As frequências naturais foram obtidas analisando-se a amplitude máxima das forças normais nos pneus, ângulo de arfagem e rolamento da massa suspensa e outras variáveis (respostas do veículo à excitação imposta na roda dianteira esquerda). A roda esquerda dianteira do veículo foi excitada em laboratório com movimento harmônico aleatório cujo power spectral density mostra uma faixa relativamente plana na faixa de 0 a 22 Hz. As frequências naturais foram obtidas analisando-se o PSD da resposta do veículo medida nos eixos e na massa suspensa. As frequências naturais da massa suspensa e não suspensa obtidas teoricamente foram comparadas com as obtidas no ensaio em laboratório. O conhecimento das frequências naturais da massa suspensa e não suspensa é o primeiro passo para a análise do ride do veículo. Os resultados práticos e teóricos mostraram-se próximos mostrando que o programa computacional desenvolvido em MatLab Simulink é uma opção para o projeto e otimização da suspensão de veículos comerciais. / This study has the natural frequencies and its respective ways of vibration the lifted mass and not lifted of a commercial vehicle through a computerized program developed at MatLab Simulink. The wheels of this vehicle are excited on the theoretic model with harmonic frequency signals continuously variable from 0 to 40 Hz and from 0 to 4 Hz, ranges that have the natural frequencies of the lifted mass and not lifted. These natural frequencies were obtained by analyses of the maximum amplitude of the normal strength on the tires, pitch angle, riding of the lifted mass and variables (reaction of the vehicle to the excitement stressed on the front left wheel). The front left wheel was excited in lab in harmonic random motion of which the power spectral density shows a range reasonable steady at the range of 0 to 22 Hz. The natural frequencies were obtained by the analyses of the PSD the reaction of the vehicle measured on the axels and the lifted mass. The natural frequencies of the lifted and not lifted mass theoretically obtained were compared with the ones obtained at the lab. The data on the natural frequencies of the lifted and not lifted mass is the first step to the analyses of the ride of the vehicle. The practical and theoretical results appear to close showing that the computerized program developed at the MatLab Simulink is an option for the project and suspension upgrades on commercial vehicles.
4

Determinação das freqüências naturais e modos de vibrar de um veículo de dois eixos através de um programa computacional em Matlab-Simulink / Determination of the natural frequencies and ways to vibrate of a vehicle of two axles through a computational program in MatLab-Simulink

Hudson Tadeu Ferreira 10 December 2003 (has links)
Este trabalho obtém as frequências naturais e seus respectivos modos de vibrar da massa suspensa e não suspensa de um veículo comercial através de um programa computacional desenvolvido em MatLab Simulink. As rodas do veículo são excitadas no modelo teórico com sinais harmônicos de frequência continuamente variável de 0 a 40 Hz e de 0 a 4 Hz, faixas que contém as frequências naturais da massa suspensa e não suspensa. As frequências naturais foram obtidas analisando-se a amplitude máxima das forças normais nos pneus, ângulo de arfagem e rolamento da massa suspensa e outras variáveis (respostas do veículo à excitação imposta na roda dianteira esquerda). A roda esquerda dianteira do veículo foi excitada em laboratório com movimento harmônico aleatório cujo power spectral density mostra uma faixa relativamente plana na faixa de 0 a 22 Hz. As frequências naturais foram obtidas analisando-se o PSD da resposta do veículo medida nos eixos e na massa suspensa. As frequências naturais da massa suspensa e não suspensa obtidas teoricamente foram comparadas com as obtidas no ensaio em laboratório. O conhecimento das frequências naturais da massa suspensa e não suspensa é o primeiro passo para a análise do ride do veículo. Os resultados práticos e teóricos mostraram-se próximos mostrando que o programa computacional desenvolvido em MatLab Simulink é uma opção para o projeto e otimização da suspensão de veículos comerciais. / This study has the natural frequencies and its respective ways of vibration the lifted mass and not lifted of a commercial vehicle through a computerized program developed at MatLab Simulink. The wheels of this vehicle are excited on the theoretic model with harmonic frequency signals continuously variable from 0 to 40 Hz and from 0 to 4 Hz, ranges that have the natural frequencies of the lifted mass and not lifted. These natural frequencies were obtained by analyses of the maximum amplitude of the normal strength on the tires, pitch angle, riding of the lifted mass and variables (reaction of the vehicle to the excitement stressed on the front left wheel). The front left wheel was excited in lab in harmonic random motion of which the power spectral density shows a range reasonable steady at the range of 0 to 22 Hz. The natural frequencies were obtained by the analyses of the PSD the reaction of the vehicle measured on the axels and the lifted mass. The natural frequencies of the lifted and not lifted mass theoretically obtained were compared with the ones obtained at the lab. The data on the natural frequencies of the lifted and not lifted mass is the first step to the analyses of the ride of the vehicle. The practical and theoretical results appear to close showing that the computerized program developed at the MatLab Simulink is an option for the project and suspension upgrades on commercial vehicles.
5

Dynamic Architectural Simulation Model of YellowCar in MATLAB/Simulink Using AUTOSAR System

Soltani, Saeed 28 September 2016 (has links)
The YellowCar at the professorship of computer engineering of TU Chemnitz is a demonstration vehicle. The car is equipped with multiple networked Electronic Control Unit (ECU)s. There are regular software and hardware updates. Before introduction of any new update, it is essential to test the behavior of the car. This can be done through simulation. Since the majority of the ECU in YellowCar are AUTOSAR based, several AUTOSAR simulation tools can be used to do so. However non-AUTOSAR ECU applications can still not be simulated in these tools. Moreover simulating with such tools need the whole application to be implemented and also very expensive. Simulink is one of the most powerful tools for the purpose of Model-in-the-Loop (MIL) testing which is a popular strategy in the embedded world. The scope of this Master thesis is analyzing the YellowCar and its architecture to develop a dynamic Simulink architectural model that can be modified and extended to facilitate future updates. The outcome of this thesis is an implementation of a model for the YellowCar which allows both AUTOSAR and non-AUTOSAR ECUs to be simulated as one system. Also the model supports extension by easy addition of new modules like ECU or sensor through a graphical user interface.
6

Autonomous Filming of Test Cars : Application integration and autonomous control approach

Prasanna Bhubalan, Suriya, Dziadak, Damian January 2016 (has links)
Before vehicles that go to sale for public it goes through many stages of testing in different fields. All types of pre-production cars are the vehicles that come after prototypes which allow the OEM to find out possible issues by running different categories of tests. One of the most important fields of test is regarding safety. When it comes to autonomous cars, where safety is crucial, the number of tests to carry out, time for handling them and their complexity is increased. To reduce costs, complexity and time some of them might be simulated. After the analysis is done the cars have to be tested in real time to collect more data, not only from car sensors but also through observation from the tests filmed. This thesis contains an overview of whole project leading to develop an autonomous platform, driving after autonomous car and controlled by simulation environment and solving major issues of the project. The filming of autonomous cars remotely had two major issues. One of the issues was to integrate all the different software and platforms. The trajectories of the autonomous cars were controlled in different software and the trajectories of the RC were managed in different software. The solution to integrate all the software and platforms is shown in this thesis. The second issue was to make the RC car to follow the waypoints that are generated by simulation and by communicating with real car using a PID controller. The project is prepared for future improvements, like installing a camera to the RC car which will follow predefined test independently.
7

The Integration of MATLAB and Embedded Controller for Control Application

Sun, I-chin 03 February 2004 (has links)
In recent years, the requirement for embedded controllers has been steadily on the increase due to the development of computers, communication and consumptive products. In order to overcome the pressure of short life-time and rapid changing rate of products, however, related industries have been engaged in improving their design to shorten the time to market and to lower the cost. Therefore, a new concept, rapid controller prototyping, has been proposed to solve the problem with the development of controllers. However, most of the proposals are expensive and restricted in the choice of software and hardware, and aren¡¦t adequate for research. To solve the problems above, this paper has chosen MATLAB/Simulink, Real-Time Workshop, a software widely used by the academic community, as tools to study rapid controller prototyping. Here, we also focus on the establishment of the developing platform. Then we design, simulate and test the controller on the platform established. Finally, we apply the controller to the physical plant. By doing so, this paper expects to solve current problems in the development of controllers.
8

Dynamic Simulation and Economic Analysis of an Isolated Hybrid Wind Diesel System

Selony, Wilson 24 June 2008 (has links)
An isolated hybrid system comprised of a dispatchable and a non-dispatchable power generation sources, is proposed to supply the load of a remote village in the west region of Haiti. The wind speed data and load data of this remote village are used to study the system. The non-dispatchable generation comes from a nature-dependent wind turbine, and the dispatchable one is a diesel generator. Using MATLAB/Simulink, dynamic simulations are performed to investigate the interaction between these two power sources for the load management, and the voltage and frequency behaviors during wind speed and load variations. Economic analyses of the system are also conducted. The cost of energy (COE), energy payback time (PBT), internal rate of return (IRR) and avoided cost (AC) of CO2¬, NOx and PM (Particles Materials) of the hybrid system are computed, and results are compared with those of the baseline diesel only case. Simulation results show that the wind turbine and the diesel generator can be operated suitably in parallel, and the economic analyses show the positive benefits of wind generation in reducing COE and increasing the avoided cost (AC) of emitted pollutions.
9

Modeling, Simulation and Optimization of Residential and Commercial Energy Systems

Bregaw, Mohamed Abdussalam 12 August 2013 (has links)
A Residential Energy Management System (REMS) in smart grid provides capability to manage a daily load curve in order to reduce power consumption and energy cost. Consequently, (REMS) offers significant benefits for both the electricity suppliers and consumers in terms of control and schedule time of use of major appliances. In recent years, however, the rate of energy demand has increased rapidly throughout the world while the price of energy has been fluctuating. Numerous methods for (REMS) are used; this thesis analyzes many candidate scenarios during peak load periods comparing to the tariff to reduce the usage and its associated costs. It presents simulated results of proposed (REMS) to provide an automated least cost demand response. The main approach will be to ensure the satisfaction of the requirements with constraints on efficient use of energy. Multiphasic system behaviors of smart appliances in (REMS) with a realistic manner are proposed. / This thesis examines many mathematical models of home appliances in order to calculate the physical quantities that reflect the parameters’ impact and the system behavior. Main contribution determines the optimal solution of (TOU) problem to reduce energy cost and determine the best operation time by using (Linear optimization technique).
10

Optimalizace datové komunikace po silnoproudých vedeních / Optimization of data communication over high-voltage lines

Minárik, Peter January 2010 (has links)
The thesis deals with analysis of the PLC (Power Line Communication) system for data communications through powerlines. In the introduction describes the technology of data transmission through the energy network and is divided into categories corresponding with the explanation of the various specifications and features. Different types of coding, affecting the transmitted signal interference and modulation techniques used in a PLC are also described. The practical part is made up of telecommunications network model with transmission channel realized as additive white noise. The model can setup different types of modulation and coding in relate with the signal to noise ratio and bit error rates. The individual blocks settings are described in detail. The model was simulated. The results of simulation are displayed and evaluated at the end of work.

Page generated in 0.0651 seconds