In many economic units where only single-phase voltage is available arises the need of using the induction motors of the power in the range to 5kW. Standard single-phase motors of such a power in practice do not exist. Therefore, the paper presents and analyses the...

The paper presents an analysis of the effect of a group of asymmetric receivers of R,L type on the battery of static capacitors and a synchronous machine connected to a common low-voltage network of an industrial plant, supplied from an own transformer. In result o...

The paper deals with mathematical modelling of two-stage frequency converter. There are used two special methods of investigation. The first one, method of complex conjugated amplitude, is used for steady-state investigation. The second one, orthogonal Park/Clarke transformation is suitabl...

This paper deals with a calculation of losses in winding of the superconducting transformer 1MVA. The idea of this usage originated in the SKODA Research Ltd., Pilsen. 5kVA model of this transformer was made with co-operation AS CR, UWB Pilsen, MFF Prague, Skoda Researc...

This work deals with the design and experimental verification of a DC linear electromagnetic actuator using power effect of the magnetic field in ferromagnetic material.

The paper deals with a particular method for analysis strongly nonlinear systems. The main emphasis is placed on differentiation of chaotic behavior of systems from other types of behavior like periodical, quasi-periodical or stochastic behavior.

The paper deals with transient phenomena on non-homogenous transmission line. The problem is solved numerically in time domain, the transmission line with space varying capacitances and inductances is considered. Practical examples are evaluated to prove an efficiency of proposed algorithm.

The publication considers significance of the disturbances occurring in technological/ electric systems. The classical approach to the theory of information transmission and its new meaning is presented. An attempt is made to determine the unaddressed information. An example of application o...

A filter design of coupled band – pass filters is very often used in practise because exhibit smaller spread of filter elements then filter ladder configurations. In comparison to cascade synthesis method enable this type of filters to reach smaller filter element sensitivit...

At first, the paper shortly deals with magnetic materials used in this application. Then the paper deals with the possibility of creating homogeneous magnetic field by two permanent magnets arrangement. At the end, it deals with possibility of generation of two levels homoge...

This paper presents the applications of the level set function for identification the unknown shape of an interface motivated by Electrical Impedance Tomography (EIT). The Mumford-Shah method was proposed in the iterative algorithm. A new approach was adopted based on a continuou...

In the paper all components of total magnetic field in the screen and onto his internal and external surface as a function variables r and Θ of cylindrical coordinates were calculated. Total current density induced in the screen of flat high current busduct was tak...

Computations of three-dimensional non-stationary electromagnetic fields described by differential equations of hyperbolic type are much more demanding and more required than computations of stationary electromagnetic fields. The objective of this paper is to describe the aspects of computing th...

The paper is stimulated by one of very prospective physical domains – magnetic cooling based on the magnetocaloric effect. Successful realization of this effect requires a magnetic circuit with permanent magnets producing very strong and uniform magnetic field and the paper deals...

Induction heating of long cylindrical nonmagnetic billets rotating in time invariable magnetic field is modelled by integral approach. The model also includes the mechanical transient. The methodology is illustrated by an example whose results are discussed.

In the paper are presented the calculations of the active and reactive power in the tubular screen of the monophase singlepole high current busduct. Into account were taken skin and internal and external proximity effect. Calculations were made using the Poynting theorem and...

The paper studies static V-A characteristics of very thin conducting fibers. The aim is to find the presence of a negative differential resistance in the characteristic. It is shown that this effect can be found only supposing that the nonlinear dependence of the metal&...

In this work, we developed a method, which is used for approximation of basic magnetic field B0 inside a specific spherical volume. This method uses Legendre multinominals expansion of magnetic flux density field measured at discrete points on spherical volume. Using optimization...

Preliminary results, theoretical and experimental, dealing with magnetic field in high current three phase net are presented. The simple formula was derived for magnetic field of thin conductor of finite length. According to the formula the flux density decreases at long distance by...

Acceleration of ferromagnetic bodies is used in a lot of various industrial and other applications. Its mathematical model consists of two ordinary differential equations describing the time evolution of the current in the field circuit and motion of the accelerated body and ...