ISSN 1805-3386

April 10, 2020


2013 No.2

Capacitive Sensors with Pre-calculable Capacitance

Ďaďo, S.

The advantages of capacitance techniques for measurement are well known and can be further enhanced by application of the design methods based on possibility to calculate their capacitance solely from electrode dimensions. The analytical calculation of capacitance is limited only to capacitors having cylindrical geometry of electrodes. Nevertheless by conformal mapping the majority of capacitive sensors can be designed. In this article besides the basic theory an example of sensor for measurement the angle of rotation is presented.


Keywords: Kelvin guard ring, capacitive sensors, analytical methods of capacitance calculation, Thompson -Lampard theorem


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The Effects of Tooth Winding Usage

Hruska, K., Sokol, M.

The article deals with tooth windings used for permanent magnet machinery, their analyses and aftereffects of their usage. The article discusses basic tooth winding properties, possibilities of examination of generated magnetic field and it studies the impact on the machine characteristics. A case study of a designed traction machine equipped with the tooth winding is presented for the purpose of result comparison.


Keywords: Differential leakage flux, Görges pattern, magnetomotive force, tooth winding, torque, winding factor


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Computation of RMS Voltage at the Point of Common Coupling in Low Voltage Three–phase Systems for Purposes of Power Quality Evaluation

Kanálik, M.

This paper describes differences of two approaches for voltage computation at the point of common coupling (PCC) in three-phase low voltage (LV) systems. The first approach is based on topology of three–wire threephase system and the second one is based on four-wire topology. The paper is aimed mainly for computation of supply voltage variations and voltage unbalance due to unsymmetrical loads. The presented method is suitable for engineers engaged in power quality evaluation.


Keywords: Nodal analysis, power quality, voltage quality evaluation, three-phase networks modeling


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Induction Motor Optimal Design by Use of Cartesian Product

Zablodskiy, N., Lettl, J., Pliugin, V., Buhr, K., Khomitskiy, S.

The problem of the automated calculation and optimal design of an induction motor is presented. Given and decided tasks of optimization by use of Cartesian product are introduced. The analysis of the obtained results is made.


Keywords: Induction motor, optimization, cortege, varied variables, Cartesian product, criteria, effective variant


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Computer Modeling and Measurement of Extended Technical Magnetic Field

Novák, M., Truhlář, M., Slavík, L., Košek, M.

A personal computer was used for both the measurement and modeling of technical magnetic fields in different areas. The field modeling uses basic physical laws from magnetism in the integral form and is performed by the numeric integration in MATLAB. The apparatus is able to measure a relatively low magnetic field. Important results are presented for the measurement of the DC field in the electromagnetic flow meter and AC field in the distribution point. Only simple models were applied, nevertheless the agreement with the experiment is good. Deviations are due to inaccuracies both in the production and experiment, predominantly. Their sources are not simple models. Therefore, the models are applicable for reliable design or analysis of devices using magnetic field.


Keywords: Computer simulation, computer controlled experiment, magnetic field modeling, Biot-Savart Law, electromagnetic flow meter, power distribution point, skineffect.


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