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Motors for automotive wipers
Sekerka, Jan ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
This thesis deals with the innovation of DC motors with permanent magnets used in automotive technology to drive wiper mechanism to reduce the volume and weight of the active materials. Potential innovations is mainly using magnets of the magnetic rare earths, such as Neodym or samarium-cobalt. Another option is to reduce the rotor to decreases the number of threads (here, it's all about, what are the requirements for performance). The result is an innovative motor, wherein the volume of the permanent magnets is reduced by 65% and total volume of the motor by 23% while maintaining the rotor parts. Also slightly raised performance with Neodymium permanent magnets.
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Utilization of artificially created weak magnetic field for navigation in 3D space
Váňa, Dominik ; Beneš, Petr (referee) ; Havránek, Zdeněk (advisor)
This master's thesis focuses on the utilization of an artificially created weak magnetic field for navigation in 3D space. The theoretical part of this work deals with the general properties of the magnetic field and with its description. The next section of the theoretical part contains an overview of measuring principles for magnetic field measurements. Based on various types of measuring principles, the thesis elaborates on commercially available miniature sensors for magnetic field measurement with a measuring range up to 10 mT. The work focuses mainly on the magnetoresistive principle and fluxgate sensors. Furthermore, the theoretical part contains descriptions of methods for modeling the magnetic field of simple permanent magnets and various magnet assemblies. Lastly, the theoretical part involves a patent search of devices used for locating magnets that are installed in an intramedullary nail, which is used in intramedullary stabilization used on fractures of human bones. By locating the magnet in the nail, it is possible to precisely determine the position of the mounting holes. The practical part of the thesis deals with the analysis of magnetic field behavior in the vicinity of various magnetic assemblies, which were modeled in COMSOL Multiphysics using the finite element method. The models were created with the aim of analysing the behaviour of the magnetic field in the vicinity of the magnets and at the same time to find possible analytical functions that could be used to determine the position of the magnet in space relative to the probe. The result of this work is an analysis of various assemblies, which contains graphs of different dependencies and prescription of polynomial functions that approximate these dependencies. Another part of the thesis is the design of a probe that serves to locate the magnetic target. The work describes two possible methods of localization. For the differential method, a user interface in LabVIEW was created. The probe based on this method is fully capable of locating the magnet in the 2D plane. The state space search method is described only in theory.
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Direct connection of permanent magnet synchronous generator to grid
Chrobák, Petr ; Mach, Martin (referee) ; Ondrůšek, Čestmír (advisor)
This thesis deals with possibility of direct grid connection of permanent magnet synchronous generator. Main benefits of PMSG are briefly compared with classical synchronous generators. There are mentioned all synchronization conditions and their modification in the case of directly grid connected PM generators. One part of this thesis is focused on the damper winding and transient currents shapes during transient state. There is also solved the effect of damper winding on currents shapes. To simulate the case of direct PMSG grid connection there is composed alternative mathematical model of PMSG. Final part of thesis is focused on the simulation of PMSG and there is also made the simulation of PMSG direct grid connection.
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Calculation and optimization of synchronous servomotor reluctance torque.
Kroupa, Martin ; Hájek, Vítězslav (referee) ; Ondrůšek, Čestmír (advisor)
This work is mainly focused on construction and design simulation of synchronous servomotor. This motor is built by 30 permanent magnets which are attached to rotor and solved in Ansoft Maxwell 14 software. The main purpose was to calculate reluctance torque, which is significant during the motor operational mode and its optimization. Ansoft Maxwell 14 can analyze in 2D mode as well as in 3D mode, for analysis it uses method of finite elements. Subjects can be analyzed in static conditions, or in any way of transient movement. Optimization in 2D, where we will change the shape in the area of air gap, will only be used as revision that the reluctance torque is bounded with this factor. The main simulations were supposed to be done in 3D model, where the role of rotation should have been taken in account to the final result. These simulations were replaced by alternative calculation. On behalf of achieved results, the optional rotation is stated in the end of my work.
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Electromagnetic damper
Mikyska, Jan ; Huzlík, Rostislav (referee) ; Ondrůšek, Čestmír (advisor)
This master´s thesis is focused on obtaining electrical energy from vibration control car using electromagnetic dampers. The primary use of the electromagnetic damper is the production of electrical energy, which can then be used to power electrical appliances in your car or battery charging. The thesis is divided into six main parts: a literature review of possible ways of getting electricity from the car damping, theoretical and mathematical analysis of problems, the choice of design with computational analysis of dampers and power calculation.
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Relative Displacement Sensor
Koutný, Petr ; Havránek, Zdeněk (referee) ; Beneš, Petr (advisor)
This thesis deals with design of optimal parameters of a relative displacement sensor, working on the electrodynamics principle. The sensor is based on the voltage induction to the coil placed in changing magnetic field. Thesis is divided into three parts: introductory, theoretical and practical. The introductory part provides basic relationships between displacement, velocity and acceleration sensors. The theoretical part contains physical concepts and describes relationships necessary for calculations and creating a model of permanent magnet in COMSOL Multiphysics. In thesis further presents patent research of electrodynamic sensors. The practical part describes the creation of the permanent magnet model and the subsequent calculation of the induced voltage in the coil in Matlab. A description of laboratory measurements follows, presenting the final comparison of the simulation and measurement results. There were found some differences, which might have been caused by incorrect calculation of the induced voltage. The final part of the thesis presents general recommendations for the design of sensor, resulting from simulations and measurements.
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The development of fail-safe magnetorheological damper
Hašlík, Igor ; Růžička, Bronislav (referee) ; Kubík, Michal (advisor)
This diploma thesis deals with an engineering design of a fail-safe magnetorheological (MR) damper capable of semi-active control. The first part of the thesis is devoted to the current state of knowledge of fail-safe MR dampers and permanent magnets contained in these dampers. The next part contains an engineering design of a fail-safe MR damper, made using FEM simulations, and its subsequent testing in terms of magnetic and hydraulic properties. Finally, a design of a fail-safe MR damper with fast response time was made and simulated using verified FEM analysis. Fast response time is ensured by limiting the generation of eddy currents in the piston core by grooving.
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Construction of BLDC motor with outer rotor
Smrž, Ondřej ; Vítek, Ondřej (referee) ; Huzlík, Rostislav (advisor)
This work is focused on the construction of the BLDC motor with outer rotor . Its mission is to become familiar with the design, basic relationships, applying this type of motor, the design procedure of magnetic circuit with permanent magnets, and then design the engine. Then there is a verification of designed motor finite element method. Finally, it summarizes the characteristics and parameters of the proposal and will compare the initial design with the other two designs, with some changes in the stator teeth.
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Cell labeling with magnetic particles
Kukhta, Dziyana ; Janoušek, Oto (referee) ; Čmiel, Vratislav (advisor)
This bachelor thesis describes the movement of cells labelled with magnetic nanoparticles in the magnetic field in the direction of the magnet. First, it describes two types of magnets: permanent magnet and electromagnet. Then, it is dedicated to magnetic field sensors, magnetic nanoparticles and their incorporation in cells, optical systems for detecting cell movement and the effect of electromagnetic fields on cells. The practical part is dedicated to the incorporation of nanoparticles in cells, the measurement of the magnetic field intensity of a neodymium magnet and an electromagnet, and the methods of electromagnet control. It also describes the effect of electromagnetic fields on fibroblasts and the concentration of nanoparticles on the ability of the labelled cells to react to a magnetic field. The last part is dedicated to the production of a flow chamber, the analysis of the movement of cells in the chamber and the subsequent capture of cells in various magnetic fields.
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