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Traction Drive with Fuel Cell
Procházka, Petr ; Chlebiš,, Petr (referee) ; Mindl,, Pavel (referee) ; Patočka, Miroslav (advisor)
The main goal of the work is development of the electric car with fuel cells. The whole complex drive will be optimized with respect of minimal consumption of the energy due to achievement of the maximal range of the car. The first part of the work deals with definition of the parameters of the whole drive in dependence of various operating state of the car. The second part describes some acceptable realizations of the traction drive. The most suitable solution was chosen for realization of the small electric car. The third part deals with principle of the minimization of the losses of the asynchronous machine in the wide range of torque and speed. The last part describes final conception and especially technical realization of the car and its parts.
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Independent Traction Drive with Low-Voltage Induction Machine
Matucha, Tomáš ; Skalický, Jiří (advisor)
This work deals with creation of an exact mathematical model of a traction drive with low-voltage induction machine (28 V) which is fed from accumulators. This model was developed in MATLAB – Simulink and consists of induction machine model, inverter model and load model. Vector Control was added to models connected together. This complex model allows considering many effects into simulations. These effects are commonly neglected, although they have significant influence on drive behaviour, especially by using low-voltage machine. It is impact of magnetic circuit saturation, impact of temperature and skin effect on winding resistance, impact of inverter nonlinearities such as on-state voltage drops on switching elements, dead times and transistors switching times. The attention was paid to determination of losses in drive parts. The correctness of the model was verified at laboratory workplace established for this purpose. The laboratory drive can be controlled by a microprocessor or by using MATLAB and dSPACE application. The influence of compensations of inverter nonlinearities and DC-link voltage ripple on higher harmonics of inverter output currents was analyzed. Furthermore, the control, which decreased resistive losses, was solved.
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Testing stand of synchronous machines
Král, Michal ; Pospišilík, Jiří (referee) ; Klíma, Bohumil (advisor)
This diploma thesis deals with a part of synchronous generator testing stand project. Thesis is focused on drive part of testing stand, the appropriate drive is chosen according to type of the tests. The attention is mainly on drive control, specifically on the configuration of frequency converter and software programming of the converter control in NI LabVIEW. Software also contains drive simulation program. Testing stands are sequentially installed and commissioned.
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Calculation of optimum slip frequency of induction motor for minimisation of its losses
Bednařík, Václav ; Patočka, Miroslav (referee) ; Vorel, Pavel (advisor)
This master’s thesis focuses on the minimisation of losses by calculation of optimum slip frequency of induction motor. The next point of this master‘s thesis is supersaturation. Supersaturation must be solved for the size of losses, because of the effect that is cause of the losses, when current increases with saturation. However current is not increase proportionally with increasing saturation, but increases several times more. This problem is included in the calculation of the slip frequency. Optimum of slip frequency is solve for modified gamma model of induction machine. In the main point of this thesis is outlined the process, how the optimum can be found. With same process were already were found the equations, but they were too extensit. In the end is solved the optimum of slip frequency be minimum of the flux density.
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Algorithms for the Control of the Induction Motor
Hundák, Vladimír ; Běloušek, Radim (referee) ; Patočka, Miroslav (advisor)
Hlavným cieľom tejto práce je vytvorenie simulácií rôznych algoritmov riadenia asynchrónneho motora a vzájomné porovnanie ich vlastností. Zaoberá sa taktiež možnosťami konfigurácie náhradného zapojenia na T-článok, -článok a -článok. Obsahuje jednak teoretický rozbor, a taktiež aj simulácie jednotlivých spôsobov riadenia spolu s podrobným návodom na ich realizáciu. Celkovo budú vykonané 3 simulácie – simulácia vektorového riadenia s orientáciou na rotorový tok, vektorového riadenia s orientáciou na statorový tok a simulácia takzvaného prirodzeného riadenia. Ide o úplne nový typ riadenia, ktorého autorom je vedúci tejto diplomovej práce. Jeho simulácia bola vôbec prvým pokusom o funkčnú realizáciu tohto typu riadenia.
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Linear Model Predictive Control of Induction Machine
Mynář, Z.
This article presents new control algorithm for induction machine based on linear model predictive control (MPC). Controller works in similar manners as field oriented control (FOC), but control is performed in stator coordinates. This reduces computational demands as Park’s transformation is absent and induction machine mathematical model in stator coordinates contains less nonlinear elements. Another aim of proposed controller was to achieve fast torque response.
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Improvement Power Parameter of Small Induction Motors
Halfar, Tomáš ; Ondrůšek, Čestmír (referee) ; Hájek, Vítězslav (advisor)
The master’s thesis Improvement power parameter of small induction motors deals with issues of lowering the losses of small induction motors. The first part introduces with design and principles of operation of induction motors. Also introduces to theoretical problematic of losses, their lowering and measuring. In the practical part there are results of the measuring the losses in the induction motor ATAS Elektromotory Náchod a.s. T22VT512 (71-0512). There are proposed methods of increasing the efficiency of induction motor due to measuring and their verification in the Maxwell software. The last part is dedicated to measuring the losses of prototype motor from ATAS and comparison of results with previous motor.
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Thermal analysis of induction machine
Grmela, Petr ; Janda, Marcel (referee) ; Skalka, Miroslav (advisor)
This thesis is dealing with thermal fields and the possibilities of their solution by a finite element method. Thereinafter thesis describe assembling a 3D model of induction machine with known parameters, and solving thermal field of the model by Ansys Workbench program and verification of these results by practical measuring on real machine.
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