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Li-ion traction battery 28V/40Ah for an electric bike
Bartošek, Martin ; Červinka, Dalibor (referee) ; Vorel, Pavel (advisor)
Thes is deals with the construction, protective circuits and lifetime of lithium ion batteries intented for powering electric bicycles. The entire battery is composed of Li-ion cells with the designation 18650 from Sanyo company, which are connected via series-parallel combination. Because of the series connection of the cells, it is necessary to add protective circuit to each cell to prevent overcharging or deep discharging, on which Li-ion cells are very sensitive. Absence of these circuits could cause irreversible damage to the entire battery pack. Life of Li-ion cells depends on many aspects. These aspects have an influence on the electric bicycle itself. They have an impact on the range and the number of charging and discharging cycles against the considerably high price of the battery.
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Device for magnetic stirring of suspension with ferromagnetic particles
Zítka, Jan ; Knobloch, Jan (referee) ; Červinka, Dalibor (advisor)
The aim of this work deals with the design and manufacture of a device for mixing of magnetic beads in solution by magnetic field. It is based on my previous bachelor thesis, where the device was created for one microtube (one sample). In this following work, the three improved variants for mixing and separation of 96 samples at one time were designed. The first variant of device, derived from functional prototype from bachelor thesis, was manufactured. First, the magnetic circuit and power converter were designed. Subsequently, the device was manufactured just for one microtube due to functionality testing. The third variant was realized only experimentally, the construction was designed in CAD program, and individual parts were created using 3D printer. As an alternative solution, which should be the compromise among electromagnetic and mechanical stirring, additional prototype was manufactured using 3D printer and CNC instrument. This prototype utilizes neodymium magnets and a stepper motor. The capability of magnetic beads mixing in solution was verified.
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Power inverter with active rectifier
Dvořáček, Daniel ; Červinka, Dalibor (referee) ; Rubeš, Ondřej (advisor)
This thesis deals with the principle of functions, constructions and possibilities of the control of inductions machines. There is also briefly described the issue of the power transducers from which the frequency converters are coming out, as well as is described here the process of designing of the power part of the converter.
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Electrical installation in family house
Dalecký, Jan ; Červinka, Dalibor (referee) ; Ondrejček, Vladimír (advisor)
In this bachelor's thesis is analyzed electrical installation of family house. It's goal is to summarize information important for designing electrical installation and subsequently create project documentation of electrical installation of three-floor family house. First part of the bachelor's thesis is dedicated to directives and demands for realization of electrical installation, which you need to lead by when creating project documentation and then assembling it in an object. The second part is focused on creating blueprints including lightning protection, low and high current installation, designing and dimensioning switchboards and technical report.
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Bánki-Michell turbine set and its maximum power point control
Marčok, Samuel ; Baculák,, Tibor (referee) ; Červinka, Dalibor (advisor)
This master’s thesis focuses on maximalization of power point of Bánki-Michell turbine and asynchronous generator set in small hydroelectric powerplant with the use of frequency converter. The first chapter addresses the history, division, and construction of hydroelectric powerplants. The following two chapters describe mechanical and electrotechnical equipment that is necessary for correct design of the control. The fourth chapter describes control possibilities of asynchronous generator and Bánki-Michell turbine set. As a verification of correctness, master´s thesis involves simulation in Matlab-Simulink. Results of this simulation are addressed in the fifth chapter, where systemic behaviour in selected control approach with the maximum power point of the set is considered. The most extensive chapter is the sixth one, because it depicts detailed description of measurement in speed or torque control. Last chapter summarizes and compares measured dependences with expected systemic behaviour derived from simulation. The conclusion of this thesis raises another possibilities for improvement of water potencial usage and describes the contribution of frequency converter.
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The high current pulse inverter
Cejpek, Miroslav ; Vorel, Pavel (referee) ; Červinka, Dalibor (advisor)
This work is devoted to welding, different types of welders and their principle, efficiency and welding using an inverter. The main responsibility of the bachelor project is design of switched welding source. Thanks to the welder as a switched power supply operating at a frequency up to 60kHz welding machine can be realize with very small footprint. The proposal involves the following parameters: Current range 55A – 135A Voltage range 13V – 36V Out voltage 80V Critical current 25A
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Emergency back-up power source with a thermoelectric cell
Kubík, Roman ; Červinka, Dalibor (referee) ; Vorel, Pavel (advisor)
This master´s thesis is directed to an research of thermoelectric cells as power sources. It is discoursing about general properities of thermoelectric cells and their using at practical aplications in the first part. Then a heating and cooling system is designed and made for a selected type of thermoelectric cell which represents the emergency back-up power source. In the next part a DC/DC step-up converter is designed for a selected type of thermoelectric cell. This converter generates the DC load voltage 12V. The converter is controlled by PWM with a carrier frequency 50kHz.
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Inverter for arc-welding
Vaculík, Josef ; Hejkrlík, Jan (referee) ; Červinka, Dalibor (advisor)
This bachelor project deals with the explanation of working principle of pulse source used as the source of welding current. It explains the activity of used single acting transmit converter and mention the others examples of converters types. Next there are mentioned powerful constructed parts of source, so input filter, pulse transformer, output inductor and powerful semiconductors components together with necessary parts converter. There are mentioned output current sensor and boards of powerful and directive parts of converter.
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Switching source in electric tractions vehicle
Škunda, Michal ; Vorel, Pavel (referee) ; Červinka, Dalibor (advisor)
The first part of this work describes the design and implementation of switch-mode power supply for control circuits for 12/2x24V 4.5A fuel cells. The introduction picks the issue of power sources in electromobiles and final design and implementation of switching power suply. The next part deals with the issues of fast-charger and generators for power transistors. It describes the structure of DC converter and control and protectin circuits of quick-charger. In the end this work describes selected driver circuits and charge tests on fast-charger as evidenced by measurements.
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High-Voltage Sources for AC Cell Electroporation
Folprecht, Martin ; Drábek,, Pavel (referee) ; Damec,, Vladislav (referee) ; Červinka, Dalibor (advisor)
This doctoral thesis deals with an application of power converters in experimental medicine. Contemporary knowledge about a relatively new electroporation method and present solutions of power converters used for this method are analyzed at this work. The main part of the thesis is focused on a design and development of a new high-voltage generator proposed to AC electroporation. The last part documents an experimental verification of its function.
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