National Repository of Grey Literature 16 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
CHANGES IN ELECTRICAL STEEL SHEETS INDUCED BY HEAT TREATMENT
Bulín, Tomáš ; Švábenská, Eva ; Hapla, Miroslav ; Ondrušek, C. ; Schneeweiss, Oldřich
Surface coating of electrical steel sheets is very important due to minimizing eddy current losses in electrical machines. The quality of coating can differ according to the composition. The coating layer has limited heat stability and after crossing of the guaranteed temperature it can be significantly degraded and its insulation properties may change importantly. The aim of this study is to describe changes in parameters of magnetic behavior of the non-oriented Si electrical steel sheet due to degradation of the coating by annealing in air. The parameters were acquired from the measuring of magnetic hysteresis loops on two types of samples with different excitation. The basic information on structure was obtained by optical microscopy. Acquired data are compared between samples with the damaged coating layer by annealing and the original coating layer. The results are discussed from the point of view of the possibility of using sheets with damaged insulation in electrical machines.
CHANGES IN ELECTRICAL STEEL SHEETS INDUCED BY HEAT TREATMENT
Bulín, Tomáš ; Švábenská, Eva ; Hapla, Miroslav ; Ondrušek, C. ; Schneeweiss, Oldřich
Surface coating of electrical steel sheets is very important due to minimizing eddy current losses in electrical machines. The quality of coating can differ according to the composition. The coating layer has limited heat stability and after crossing of the guaranteed temperature it can be significantly degraded and its insulation properties may change importantly. The aim of this study is to describe changes in parameters of magnetic behavior of the non-oriented Si electrical steel sheet due to degradation of the coating by annealing in air. The parameters were acquired from the measuring of magnetic hysteresis loops on two types of samples with different excitation. The basic information on structure was obtained by optical microscopy. Acquired data are compared between samples with the damaged coating layer by annealing and the original coating layer. The results are discussed from the point of view of the possibility of using sheets with damaged insulation in electrical machines.
Magnetic properties of 42CrMo4 steel
Bulín, T. ; Švábenská, Eva ; Hapla, Miroslav ; Roupcová, Pavla ; Ondrušek, C. ; Schneeweiss, Oldřich
Low alloyed high-grade chrome-molybdenum ferritic steel was investigated from the point of views of magnetic properties in dependence on heat and mechanical treatment. This steel can be used as components of magnetic circuits or some parts in electrical equipment. The basic information on structure and phase composition was obtained by optical and scanning electron microscopy, X-ray Powder Diffraction and Mössbauer Spectroscopy. The temperature stability of the material was proved by measurements of temperature dependences of magnetic moment. The magnetic parameters were obtained by measuring of magnetic hysteresis loops in dependence on saturation field and their frequencies. The results are discussed from the point of view of possible applications as a magnetic material in the very extremely environment, where high mechanical stresses and elevated temperatures can occur.
MAGNETIC AND TRANSPORT PROPERTIES OF 41CRMO4 STEEL
Bulín, T. ; Hapla, Miroslav ; Roupcová, Pavla ; Ondrůšek, Č. ; Schneeweiss, Oldřich
We have measured magnetic parameters and electrical resistivity of 41CrMo4 steel. It consist ferrite, Cr7C3 and Cr23C6 type of carbides. The\nmeasurements of temperature dependences of magnetic moments and electrical resistivity confirm phase stability of ferrite. The room temperature resistivity, saturation magnetization at room temperature, as well as AC measurements was measured. The power losses are strongly dependent on frequency and excitations.
INFLUENCE OF LASER CUTTING AND PUNCHING ON MAGNETIC PROPERTIES\nOF ELECTRICAL STEEL M470-50A
Bulín, Tomáš ; Švábenská, Eva ; Hapla, Miroslav ; Ondrůšek, Č. ; Schneeweiss, Oldřich
Electrical steel M470-50A belongs to the most often used materials in electrical machines. Due to this fact, it is desirable to know the magnetic parameters after processing raw sheets into the required shape. Basic parameters of mechanical, electrical, and magnetic properties of the sheets are usually obtained from the producer but the magnetic properties are changing in dependence on additional machining processes. The aim of this study is to describe changes in parameters of magnetic behavior after punching, laser and spark cutting of the original sheets. The basic information of structure was obtained by optical and scanning electron microscopy. The magnetic parameters were acquired from the measuring of magnetic hysteresis loops in dependence on saturation fields and frequencies. The results are discussed from the point of view of applied\ncutting technology with the aim to obtain the best magnetic parameters and consequently a higher efficiency of the final product. Results can be used as input parameters in simulation of the electrical machine.
Induction Machine Operation Mode Type Effect Onto The Losses
Skalka, Miroslav ; Schreier, Luděk ; Janda, M. ; Ondrůšek, Č.
This paper deals with analysis of losses behavior of Induction Machine for both operation mode types (motor/generator). The purpose of this work is the definition of eqiuvalent circuit parameters and theirs non-linear behavior depending on various factors - slip, mechanical torque, temperature. In this paper would be presented behavior of iron losses and joule losses of rotor and stator with specific parameters behavior. The whole analysis is done in ANSYS (by FEM) and MATLAB program.
Influence of Induction Machine Operation Mode Type Onto The Equivalent Circuit
Skalka, Miroslav ; Schreier, Luděk ; Janda, M. ; Ondrůšek, Č.
This paper deals with analysis of Induction Machine equivalent circuit parameters for both operation mode types (motor/generator). The purpose of this work is the definition of equivalent circuit parameters and theirs non-linear behavior depending on various factors - slip, mechanical torque, temperature. The temperature influence for longitudinal resistances is done - which means, the stator and rotor resistance value depends on passing current. At the end an electromagnetic field comparison for the same operation point in both operation mode types will be presented. The whole analysis is done in ANSYS (by FEM) and MATLAB program.
Electromagnetic Field Calculation of IM for Different Equivalent Circuit Parameters
Skalka, Miroslav ; Schreier, Luděk ; Ondrůšek, Č.
This paper contains a calculation of electromagnetic field distribution of Induction machine for different equivalent circuit parameters due to the loads - each step is calculated for different rotor and stator currents. The definition of parameters and the real values of rotor and stator currents were presented on the XVI. Inter. Symposium on Electric Machinery in Prague. These data were used for a calculation of electromagnetic field distribution of Induction Machine (IM) by finite element method in ANSYS.
Definice parametrů náhradního schématu a výpočet elektromagnetického pole asynchronního stroje
Skalka, Miroslav ; Ondrůšek, Č. ; Schreier, Luděk
This paper deals with mathematic and graphic description of non-linearity parameters of induction machine (IM) equivalent circuit due to measured data: no-load, short-circuit and load test. The real values of rotor currents in each of rotor bar for these parameters are calculated. This paper also contains calculation of electromagnetic field distribution by finite element method in ANSYS.
Inverse kinematic modelling in simmechanics and application for robotics mechanisms
Grepl, Robert ; Ondrůšek, Č.
This paper deals with the design of inverse kinematic model in software Matlab-SimMechanics. Presented approach is applied to particular robotic mechanism, thepanthographical leg of quadruped walking robot. It is possible to use created model as an approximation methodtraining data generator or directly in computation in the Matlab.

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