The objective of this Thesis is to investigate the phenomenon of voltage unbalance on electrical wind power systems. A large part of this work is the literature review of all relative work that has been done so far. This serves first as a guideline to define and measure voltage unbalance and second as a tool to spot open research questions that can inspire future work. A case study is then used to investigate the voltage unbalance at a wind farm in Näsudden, Gotland. Using real-time measurements and a simulation of the power system in MATLAB/Simulink, an evaluation of the propagation of the voltage unbalance from the distribution to the turbine level is carried out. The effect that different transformer connection types have on the propagation is studied through simulations. Many assumptions and simplifications had to be made due to several limiting factors during this work, mainly related to time and data restrictions. The main result shows that when Delta – Wye Grounded and Wye – Wye Grounded transformers are used, the unbalance is halved when it passes to the turbine side. On the other hand, when Wye Grounded – Wye Grounded configuration was used, the unbalance was unaffected. The results also include a comparison of the use of different indices to quantify a voltage unbalance.

This thesis gives different views on the modeling and simulation of physical systems, especially together with embedded systems, forming mechatronic systems. The main considered application domain is automotive. One motivation behind the work is to find suitable representations of physical systems to be used in an architectural description language for automotive embedded systems, EAST-ADL2, which is implemented as a UML2 profile, and uses concepts from both UML and SysML. As a part of the thesis, several languages and tools are investigated, including bond graphs, MATLAB/Simulink, Ptolemy II, Modelica, MATLAB/Simscape and SysML. For SysML, the modeling of continuous-time systems and how it relates to MATLAB/Simulink and Modelica is evaluated. A case study of an electric power assisted steering is modeled to show the differences, the similarities and the usage of the above mentioned languages and tools. To be able to classify the tools and languages, five realization levels were developed: Physical modeling models Constraint models Continuous causal models Discretized models Discretized models with solver and platform implementation By using these realization levels, models, tools and modeling languages can be classified, and transformations between them can be set up and analyzed. As a result, a method to describe the simulation behavior of a MATLAB/Simulink model has been developed using SysML activity diagrams as an approach to achieve integrated system models. Another result is an evaluation of the parametric diagrams of SysML for continuous-time modeling, which shows that they do not enable “physical modeling”, i.e. modeling the topology of the system and getting the underlying equations out of this topology. By including physical ports and physical connectors to SysML internal block diagrams, this could be solved. The comparison also shows many similarities between the languages. The results led to a more detailed investigation on conjugate variables, such as force and velocity, and electric current and voltage, and how these are treated in various languages. The thesis also includes two industrial case studies: one of a twin-screw compressor, and one of a simulation environment for automotive fuel-cell systems. Conclusions are drawn from these models, referring to the realization levels. / QC 20100810

A dynamic flight model of a jet trainer aircraft is developed in MATLAB-SIMULINK. Using a six degree of freedom mathematical model, non-linear simulation is used to observe the longitudinal and lateral-directional motions of the aircraft following a pilot input. The mathematical model is in state-space form and uses aircraft stability and control derivatives calculated from the aircraft geometric and aerodynamic characteristics. The simulation takes the changes in speed and altitude into consideration due to pilot input and demonstrates the non-linearity of the aircraft motion. The results from the simulation are compared with the results from flight characteristics manual of the actual aircraft to validate the mathematical model used. The simulation is carried out for a number of airspeed and altitude combinations to examine the effect of changing speed and altitude on the aircraft dynamic response.

Les travaux présentés dans cette thèse portent sur la modélisation et la simulation d'un microsystème multidisciplinaire composé de dispositifs qui sont conçus dans des domaines différents: électromécanique, électronique analogique et numérique, et électrochimique. <br />L'objectif est de proposer des prototypes virtuels d'un microsystème dit autonome. Ce microsystème permet de générer à partir de vibrations mécaniques, une énergie électrique qui sert à alimenter tout le dispositif, et le rendre électriquement indépendant.<br />Une méthode de modélisation collaborative sous l'environnement MATLAB/Simulink est proposée afin d'étudier le comportement du microsystème. Ceci est réalisé à différents niveaux de détails en se basant sur deux approches de simulations. La première permet de vérifier le comportement du prototype virtuel dans un même environnement et de le valider par simulation globale. La deuxième approche consiste à simuler le système complet en faisant appel à l'interface de cosimulation avec le langage VHDL sous ModelSim. <br />Les résultats de simulation confrontés aux mesures effectuées sur le prototype physique ont montré la fiabilité de la méthode proposée.

Les travaux présentés dans cette thèse portent sur la modélisation et la simulation d'un microsystème multidisciplinaire composé de dispositifs qui sont conçus dans des domaines différents: électromécanique, électronique analogique et numérique, et électrochimique. L'objectif est de proposer des prototypes virtuels d'un microsystème dit autonome. Ce microsystème permet de générer à partir de vibrations mécaniques, une énergie électrique qui sert à alimenter tout le dispositif, et le rendre électriquement indépendant. Une méthode de modélisation collaborative sous l'environnement MATLAB/Simulink est proposée afin d'étudier le comportement du microsystème. Ceci est réalisé à différents niveaux de détails en se basant sur deux approches de simulations. La première permet de vérifier le comportement du prototype virtuel dans un même environnement et de le valider par simulation globale. La deuxième approche consiste à simuler le système complet en faisant appel à l'interface de cosimulation avec le langage VHDL sous ModelSim. Les résultats de simulation confrontés aux mesures effectuées sur le prototype physique ont montré la fiabilité de la méthode proposée.

In this thesis, the concept of virtual reality has been elaborated in the context of games, industrial design and manufacturing. The main purpose of this master’s thesis is to create a virtual environment for games that are near to the reality and according to the human nature through aspects like better interface, simulation, lights, shadow effects and their types. The importance of these aspects regarding realistic virtual environment is complemented through the comparison between two environments i.e. desktop and CAVE on a flight simulation program.

This work builds on a semester project 2. from the winter semester of this academic year. The aim of this thesis is the design of converter using semiconductor components based on SiC technology. This converter is used in the construction of quick charger for electric vehicles. The design of this converter must be based on the requirements for compliance voltage safety. It describes the design of power components used in the construction of this facility, the determination of their losses and determines the overall efficiency of the converter. There is also proposed mathematical model of high-frequency transformer and made his simulation in Matlab-Simulink.

This master thesis describes the design of a DC/DC converter for one photovoltaic panel with a 250 W peak power. The master thesis is divided into parts dealing with detailed design of power electronics, analog circuit design, description of control MPPT algorithms and software for control circuit. The chapter with the mathematical modeling of the converter created in the Matlab Simulink was added beyond the assignment.

This diploma thesis deals with the design of the asynchronous mathematical model, and creation its model in MATLAB Simulink. And by creating different types of asynchronous motor control. At the beginning of the work there are theoretical knowledge about transformation of quantities into coordinates, which are needed for creation of mathematical model and further for machine control. Furthermore, control logarithms are created from these transformed quantities, which can be used to control the torque or engine speed. It is a constant magnetic flux control, scalar control, vector control, and ultimately direct torque control. All derived control algorithms have been tested in MATLAB Simulink. Where were simulations of investigated quantities.

The thesis focuses on the power management support of battery systems in charging mode and charging systems for electric vehicles in the LV network. The thesis includes an overview of the distribution network of the Czech Republic, means of voltage regulation and the existing legislative framework for the connection of charging systems. The thesis describes the methods of active and reactive power control depending on the voltage and frequency. The practical part focuses on the simulation of grid support at different penetration levels of BESS and EVC in MATLAB Simulink and the verification of the support function on a laboratory system. In the last part, the methods of implementing the control system for BESS and EVC operating in the LV grid are specified.