This work deals with three-phase active rectifier control. In first, theoretical part it describes several control strategies with focus on voltage oriented control. For this type of control a design is worked out, and created model and its simulation is described. Second, practical part deals with realisation on microcontroller TMS320F28335, which is main processing unit of device lent by company Elcom. Therefore in this part abilities and settings of the controller along with developped control algorithm are described. Reached results of measurement are then presented and in the conclusion they are evaluated.

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Electric and hybrid-electric vehicles lean heavily on intricate control algorithms to provide smooth, reliable, and secure operations under any driving conditions. Three distinct supervisory control strategies have been developed, each aiming to improve reliability and vehicle performance of a dual-motor electric vehicle equipped with an all-wheel-drive, fully electric powertrain. These algorithms are adept at dynamically modulating and constraining the torque provided to the wheels, leveraging two autonomous permanent magnet electric drive units. This study utilizes a vehicle model jointly provided by MathWorks and General Motors in partnership with industry sponsors. The these strategies were implemented in the model and enhanced the performance, vehicle range, energy consumption, regenerated energy using specific EDUs provided by sponsors. Adhering to a systematic engineering iterative method, the emphasis was heavily placed on simulation and modeling during the development and validation of these strategies. Simulations ensured robust testing before field implementation, emphasizing software modeling's vital role.

<p dir="ltr">In this thesis, a MATLAB model was used to simulate a 2-vehicle platoon where the lead truck is a conventional class 8 vehicle while the key parameters of the following truck was tested in various road conditions to minimize Inter vehicular Distance (IVD) and maximize fuel savings while ensuring safety</p>

The development of a numeric simulation for predicting the performance of an Ocean Current Energy Conversion System is presented in this thesis along with a control system development using a PID controller for the achievement of specified rotational velocity set-points. In the beginning, this numeric model is implemented in MATLAB/Simulink® and it is used to predict the performance of a three phase squirrel single-cage type induction motor/generator in two different cases. The first case is a small 3 meter rotor diameter, 20 kW ocean current turbine with fixed pitch blades, and the second case a 20 meter, 720 kW ocean current turbine with variable pitch blades. Furthermore, the second case is also used for the development of a Voltage Source Variable Frequency Drive for the induction motor/generator. Comparison among the Variable Frequency Drive and a simplified model is applied. Finally, the simulation is also used to estimate the average electric power generation from the 720 kW Ocean Current Energy Conversion System which consists of an induction generator and an ocean current turbine connected with a shaft which modeled as a mechanical vibration system.

Η παρούσα διπλωματική εργασία πραγματεύεται την μελέτη και ανάλυση ενός υψηλής τάξης μοντέλου διπλά τροφοδοτούμενης επαγωγικής μηχανής, κατάλληλο για μελέτες μεταβατικής κατάστασης αιολικών συστημάτων. Αρχικά, γίνεται μία εισαγωγή στις ανανεώσιμες πηγές ενέργειας, με ιδιαίτερη αναφορά στην αιολική ενέργεια. Κατόπιν, περιγράφονται οι διάφοροι τρόποι ταξινόμησης των ανεμογεννητριών που υπάρχουν σήμερα, τα δομικά στοιχεία αυτών, καθώς και η αεροδυναμική τους μετατροπή. Ακολουθεί η γενική παρουσίαση μίας διπλά τροφοδοτούμενης επαγωγικής γεννήτριας. Προκειμένου να γίνει μελέτη των μεταβατικών καταστάσεων, παρουσιάζεται το δυναμικό μοντέλο και ο διανυσματικός έλεγχος μίας διπλά τροφοδοτούμενης επαγωγικής γεννήτριας υψηλής τάξης. Εν συνεχεία, αναλύεται -βάσει εξισώσεων- η συμπεριφορά της εν λόγω γεννήτριας σε τριφασικές και ασύμμετρες βυθίσεις τάσεων, που είναι αποτέλεσμα διαφόρων μεταβατικών καταστάσεων. Τέλος, γίνεται η προσομοίωση ενός αιολικού πάρκου, που περιλαμβάνει ανεμογεννήτριες αυτού του τύπου και μελετώνται διάφορες διαταραχές στο σύστημα, όπως: συμμετρικά και ασύμμετρα βραχυκυκλώματα, απότομες μεταβολές της ταχύτητας του ανέμου, απώλεια και μεταβολή φορτίου. Η προσομοίωση πραγματοποιείται με τη βοήθεια του λογισμικού MATLAB/Simulink, έκδοση 7.6. / The subject of this thesis is the study and analysis of a high-order model of a doubly-fed induction machine (DFIM), suitable for unbalanced condition studies on a wind farm. At first, an introduction is made of the renewable energy sources, with special mention of the wind energy. Then, there is the description of the different types of wind turbines than exist nowadays, their components and their aerodynamic conversion. A general presentation of a doubly-fed induction generator (DFIG) is made and after that, for the study of disturbances, the dynamic model and the vector control of a high-order model of a doubly-fed induction generator are presented. Through mathematical equations, the performance of this generator under voltage dips is then described, result of various transition phenomena. Finally, the simulation of a wind farm that includes wind turbines of this type, is made and several disturbances on the grid, such as: symmetrical and asymmetrical faults, sudden changes of the wind speed, loss and change of the load. Simulation is made with the use of the software MATLAB/Simulink, version 7.6.

Dizertační práce je zaměřena na softwarově definované přijímače určené k úzkopásmové družicové komunikaci. Komunikační kanály družicových spojů zahrnujících komunikaci s hlubokým vesmírem jsou zatíženy vysokými úrovněmi šumu, typicky modelovaného AWGN, a silným Dopplerovým posuvem signálu způsobeným mimořádnou rychlostí pohybu objektu. Dizertační práce představuje možné postupy řešení výpočetně efektivní digitální downkonverze úzkopásmových signálů a systému odhadu kmitočtu nosné úzkopásmových signálů zatížených Dopplerovým posuvem v řádu násobků šířky pásma signálu. Popis navrhovaných algoritmů zahrnuje analytický postup jejich vývoje a tam, kde je to možné, i analytické hodnocení jejich chování. Algoritmy jsou modelovány v prostředí MATLAB Simulink a tyto modely jsou využity pro ověření vlastností simulacemi. Modely byly také využity k experimentálním testům na reálném signálu přijatém z družice PSAT v laboratoři experimentálních družic na ústavu radioelektroniky.

Hardware-in-the-loop (HiL) is a concept for testing physical equipment by connecting itto a mathematical representation (model) of the physical process. HiL-testing reduces thecost and saves time before testing the physical equipment (hardware) on the real (physical)process. The physical process chosen for this study is wire+arc additive manufacturing(WAAM), an advanced additive manufacturing (AM) technology that deposits metalbased material layer-by-layer. In this study, simulations of the robot path are carried outwhile the physical robot performs a physical process (additive manufacturing). In robotadditive manufacturing, the desired CAD model is currently sliced down into layers usingslicer software, and the layers are then translated into a path. The robot then moves alongthe path of these pre-defined layers to produce a three-dimensional structure. The heightof the produced structures and desired CAD models have deviations because of processinstabilities and temperature variations among other factors. The robot path should beupdated every time a layer is printed to compensate for the height differences. This isachieved by parametrizing the CAD model, i.e., the CAD model of the structure to beprinted is replaced by a mathematical equation (model). In this study, the mathematicalmodel is updated for each layer in real-time with feedback data from sensors that monitorthe additive manufacturing process. The concept of updating a mathematical model andexecuting it in real-time is called real-time simulation (RTS). In this study, a HiL-basedreal-time simulation setup has been developed, which predicts the required printing layerheight and the number of layers (based upon the latest feedback data from the monitoringsensors), and the required height of the structure. By combining hardware and software,a cyber-physical system has been created, enabling the transition from automation toautonomous robotics and contributing to Industry 4.0.

The dissertation thesis deals with a WLAN and Bluetooth systems coexistence. A Bluetooth standard works in an unlicensed frequency band 2,402 – 2,480 GHz. This frequency band is also used by an IEEE 802.11b/g standard (Wi-Fi) which is the most extended representative of WLAN networks. Because Bluetooth and Wi-Fi systems operate in the same frequency band, a mutual signal degradation may appear, when devices are collocated in the same area. In the first part of the dissertation thesis there is a brief summary of 2,402 - 2,480 GHz frequency band regulations and its usage. There are described physical layers of Bluetooth and IEEE 802.11b/g standards and techniques used for a collision avoidance. The main part of the dissertation thesis deals with a development of a new Matlab Simulink model for investigations of the Bluetooth and Wi-Fi standards coexistence. Physical layer models and results of the coexistence simulations are verified by a measurement in real conditions with a help of a modern vector signal analyzer. The results are presented in a graphical form and a brief summary is attached at the end of each chapter. Corresponding tables of simulated and measured values are available in the enclosed CD.