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  • 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.
21

OpenModelica Interactive Simulation using an OPC UA client

Fors Johansson, Christoffer January 2017 (has links)
Simulating a model of a complex physical system can beuseful in order to obtain a deeper understanding of the system.OpenModelica is an open-source, modeling and simulation environmentin which such a simulation could be performed. This thesispresents a design and implementation of an interactive simulationprototype for the OpenModelica Connection Editor. After aninvestigation of the possibilities in the current OpenModelicaenvironment, several requirements were determined about howinteractive simulation should look and work. A prototype wasdeveloped based on these requirements. As a result, the prototypecan act as a base for applying further functionality to theinteractive simulation in both parallel and future works.
22

EVALUATING THE RELIABILITY OF FMI CO-SIMULATION FOR VALIDATION

Mikelöv, Richard, Bergsten, Andreas January 2023 (has links)
No description available.
23

Development of EMT components and reference grid in OpenModelica

Fernandez Horcajuelo, Alba January 2021 (has links)
Power systems simulation tools enable to study and evaluate the performance of electrical power systems in different scenarios. This allows the development and implementation of new solutions to the challenges electrical grids face nowadays. In this sense, electromagnetic transient (EMT) simulation provides detailed information on the behaviour of the different components involved in the system. Moreover, among the wide range of existing tools, those based in Modelica language present certain advantages for power system simulation, such as equation- based modeling and the possibility of working in open- source environments. This project presents the development of components and reference grid in EMT formalism in the open- source environment OpenModelica, based on Modelica language. With the purpose of power system simulation, electrical components have been modeled in OpenModelica and gathered in a library for EMT simulation The performance of the different components has been validated by comparing the results of the EMT simulation of a 3buses reference grid in different case studies in OpenModelica and other EMT- based software. Furthermore, the comparison has been also established with phasor simulation in OpenModelica, enabling the evaluation of the differences between phasor and EMT simulation. The results show the main advantages and drawbacks of working with OpenModelica regarding other simulation tools and the lack of information provided by the phasor simulation, particularly in the case of a fault event. Additionally, certain difficulties encountered when working with OpenModelica have also been identified. / Simulering av kraftsystem gör det möjligt att studera och utvärdera prestandan i olika scenarion. Genom detta kan utveckling och implementering av nya lösningar på de utmaningar som elnäten står inför framöver ske. Elektromagnetisk transient (EMT)simulering ger detaljerad information om beteendet hos de olika komponenterna i systemet. Bland de många befintliga verktygen innehåller de som är baserade på Modelica- språket dessutom vissa fördelar för kraftsystemsimulering, såsom ekvationsbaserad modellering och möjligheten att arbeta i miljöer med öppen källkod. Den här uppsatsen presenterar en utveckling av komponenter och testelnät i EMT- formalism i öppen källkodsmiljö OpenModelica, baserat på programmeringsspråket Modelica. Elektriska komponenter har modellerats i OpenModelica och samlats i ett bibliotek för EMT- simulering. Målet är en detaljerad simulering av elkraftsystem. Komponenternas prestanda har validerats genom att jämföra resultatet av EMT- simuleringen av ett 3bussreferensnät i olika fallstudier i OpenModelica och annan EMT- baserad programvara. Sedan har jämförelsen även utförts med simuleringar i fasorformalism i OpenModelica. Den här jämförelsen har också möjliggjort utvärderingen av skillnaderna mellan fasor och EMT- simulering. Resultaten visar de största fördelarna och nackdelarna med att arbeta med OpenModelica njämfört med andra simuleringsverktyg. De visar också bristen på information om fasorsimuleringen, särskilt i fallet med ett elektriskt fel. Dessutom har vissa svårigheter identifierats med att arbeta med OpenModelica.
24

Создание математической модели технологического процесса энергопотребления зданий : магистерская диссертация / Creation of a mathematical model of the technological process of energy consumption of buildings

Берёзкин, И. А., Berezkin, I. A. January 2023 (has links)
Цель работы – создание математической модели технологического процесса энергопотребления здания, создание набора данных, создание нейросети для прогнозирования энергопотребления здания, выявление закономерностей и аномалий. Объект исследования – энергопотребление здания. Рассматриваются различные факторы, такие как работа системы кондиционирования, системы подачи воды, бытовые приборы, освещение помещения. Детально рассмотрена система кондиционирования. Построена математическая модель в итераторе OpenModelica, учитывающая факторы внешней и внутренней среды здания. Собран набор данных в формате .csv. Проведён анализ результатов, выявлены взаимодействия признаков системы, аномалии влияющие на энергопотребление здания. Написана нейросеть прогнозирующая энергопотребление здания, создан pipeline для выявления и визуализации аномалий. Результаты представлены на графиках, сделаны выводы. В ходе полученных результатов были предложены методы оптимизации работы системы, которые привели к экономическому и экологическому эффекту. / The purpose of the work is to create a mathematical model of the technological process of energy consumption of a building, create a data set, create a neural network to predict the energy consumption of a building, identify patterns and anomalies. The object of study is the energy consumption of the building. Various factors are considered, such as the operation of the air conditioning system, water supply system, household appliances, and room lighting. The air conditioning system is examined in detail. A mathematical model was built in the OpenModelica iterator, considering the factors of the external and internal environment of the building. Collected data set in .csv format. An analysis of the results was carried out, interactions of system characteristics and anomalies affecting the energy consumption of the building were identified. A neural network was written to predict the energy consumption of a building, and a pipeline was created to identify and visualize anomalies. The results are presented in graphs and conclusions are drawn. As a result of the results obtained, methods were proposed to optimize the operation of the system, which led to economic and environmental benefits.
25

Debugging Equation-Based Languages in OpenModelica Environment

Sjöholm, Klas January 2009 (has links)
<p>The need for debugging tools for declarative programming languages has increased due to the rapid development of modeling and simulation tools/programs. Declarative equation-based programming languages have the problem of equation systems being over-, or under-constrained. This means that the system of equations has more equations than variables or more variables than equations respectively, making the system of equations unsolvable. In this study a static debugger is implemented in OpenModelica compiler for the equation-based programming language Modelica to make it easier for the programmer or modeler to locate the equation/s causing the unconstrained system of equations. The debugging techniques used by the debugger are developed by Peter Bunus. Those techniques are able to detect unconstrained systems of equations and give solutions by identifying the minimal set ofequation/s that should be removed or which variable/s should be added to an equation/s to make the system solvable. In this study the debugging techniques for detecting and giving a solution for over-constrained system of equations are shown suitable to be used for the programming language Modelica in the OpenModelica compiler.</p>
26

Bidirectional External Function Interface Between Modelica/MetaModelica and Java

Sjölund, Martin January 2009 (has links)
<p>A complete Java interface to OpenModelica has been created, supporting both standard Modelica and the metamodeling extensions in MetaModelica. It is bidirectional, and capable of passing both standard Modelica data types, as well as abstract syntax trees and list structures to and from Java and process them in either Java or the OpenModelica Compiler.It currently uses the existing CORBA interface as well as JNI for standard Modelica. It is also capable of automatically generating the Java classes corresponding to MetaModelica code.This interface opens up increased possibilities for tool integration between OpenModelica and Java-based tools, since for example models or model fragments can be extracted from OpenModelica, processed in a Java tool, and put back into the main model representation in OpenModelica.</p><p>A first version text generation template language for MetaModelica is also presented. The goal for such a language is the ability to create a more concise and readablecode when translating an abstract syntax tree (AST) to text.</p>
27

ParModelica : Extending the Algorithmic Subset ofModelica with Explicit Parallel LanguageConstructs for Multi-core Simulation

Gebremedhin, Mahder January 2011 (has links)
In today’s world of high tech manufacturing and computer-aided design simulations of models is at theheart of the whole manufacturing process. Trying to represent and study the variables of real worldmodels using simulation computer programs can turn out to be a very expensive and time consumingtask. On the other hand advancements in modern multi-core CPUs and general purpose GPUs promiseremarkable computational power. Properly utilizing this computational power can provide reduced simulation time. To this end modernmodeling environments provide different optimization and parallelization options to take advantage ofthe available computational power. Some of these parallelization approaches are based onautomatically extracting parallelism with the help of a compiler. Another approach is to provide themodel programmers with the necessary language constructs to express any potential parallelism intheir models. This second approach is taken in this thesis work. The OpenModelica modeling and simulation environment for the Modelica language has beenextended with new language constructs for explicitly stating parallelism in algorithms. This slightlyextended algorithmic subset of Modelica is called ParModelica. The new extensions allow modelswritten in ParModelica to be translated to optimized OpenCL code which can take advantage of thecomputational power of available Multi-core CPUs and general purpose GPUs.
28

Extending Modelica with High-Level Data Structures: Design and Implementation in OpenModelica

Björklén, Simon January 2008 (has links)
<p>Modelica is an equation-based object-oriented language (EOO). PELAB at Linköping University along with the OpenModelica development group, is developing a metamodeling extension, MetaModelica, to this language along with a compiler called the OpenModelica Compiler (OMC).</p><p>The goal of this thesis was to analyze the compiler, extend it with union type support and then write a report about the extension with union types in particular and extension with high level data structures in general, to facilitate further development. </p><p>The implementation made by this thesis was implemented with the goal of keeping the current structure intact and extending case-clauses where possible. The main parts of the extension is implemented by this thesis work but some parts concerning the pattern matching algorithms are still to be extended. The main goal of this is to bootstrap the OpenModelica Compiler, making it able to compile itself although this is still a goal for the future.</p><p>With this thesis I also introduce some guidelines for implementing a new highlevel data structure into the compiler and which modules needs extension.</p>
29

Software Modeling in Cyber-Physical Systems

Shrestha, shilu January 2014 (has links)
A Cyber-Physical System (CPS) has a tight integration of computation, networking and physicalprocess. It is a heterogeneous system that combines multi-domain consisting of both hardware andsoftware systems. Cyber subsystems in the CPS implement the control strategy that affects the physicalprocess. Therefore, software systems in the CPS are more complex. Visualization of a complex system provides a method of understanding complex systems byaccumulating, grouping, and displaying components of systems in such a manner that they may beunderstood more efficiently just by viewing the model rather than understanding the code. Graphicalrepresentation of complex systems provides an intuitive and comprehensive way to understand thesystem. OpenModelica is the open source development environment based on Modelica modeling andsimulation language that consists of several interconnected subsystems. OMEdit is one of the subsystemintegrated into OpenModelica. It is a graphical user interface for graphical modeling. It consists of toolsthat allow the user to create their own shapes and icons for the model. This thesis presents a methodology that provides an easy way of understanding the structure andexecution of programs written in the imperative language like C through graphical Modelica model.
30

Extending Modelica with High-Level Data Structures: Design and Implementation in OpenModelica

Björklén, Simon January 2008 (has links)
Modelica is an equation-based object-oriented language (EOO). PELAB at Linköping University along with the OpenModelica development group, is developing a metamodeling extension, MetaModelica, to this language along with a compiler called the OpenModelica Compiler (OMC). The goal of this thesis was to analyze the compiler, extend it with union type support and then write a report about the extension with union types in particular and extension with high level data structures in general, to facilitate further development. The implementation made by this thesis was implemented with the goal of keeping the current structure intact and extending case-clauses where possible. The main parts of the extension is implemented by this thesis work but some parts concerning the pattern matching algorithms are still to be extended. The main goal of this is to bootstrap the OpenModelica Compiler, making it able to compile itself although this is still a goal for the future. With this thesis I also introduce some guidelines for implementing a new highlevel data structure into the compiler and which modules needs extension.

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