Mirosław Łukiewski

TRAFECO Sp. J. · Transformers and inductive components

The choice of materials for cores of electrotechnical devices is currently related to energy saving and global warming problems. Nanocrystalline alloys are emerging as materials for cores in these devices in addition to amorphous materials already commonly used due to their better magnetic properties at high operating frequencies. The thermal stabi...

The paper presents the effect of replacing air gaps with magnetic spacers made of three different materials. For this purpose, the technology of producing prototype cores for three-phase LLC and LCL filter chokes was developed, computer simulation of the distribution of the magnetic field lines was performed, and the magnetic properties were measur...

Power electric devices, such as line inductors or transformers, are limited by current, voltage, and operating temperature. Current is the main culprit behind the heating of all electric devices. Excess heating leads to faster degradation of the insulation and lowers the breakdown voltage. These factors determine the lifetime and reliability of the...

This paper focuses on the phenomenon of the magnetic flux density dispersion Bd on the gaps of the Fe73.5Cu1Nb3Si13.5B9 multi-gap nanocrystalline block core. Present state-of-the-art shows, that there is no comprehensive knowledge about the value of the magnetic flux density dispersion Bd on the gaps of nanocrystalline block core and the possibilit...

In this article selected optimizing issues related to the construction of the transformers worked in static converters of electro-mobile vehicles were discussed. The simulation of the effect of core magnetic material on the losses and transformer sizes have been compared. Moreover, the increase of effected – cooling due to solution of transformer c...

DC thermomagnetic properties of Fe51Co12Si16B8Mo5P8 amorphous alloy in the as-quenched and after annealing below crystallization temperature are investigated. They are related to deviations in the microstructure as revealed by Mössbauer spectrometry. Study of AC magnetic properties, i.e. hysteresis loops, relative permeability and core losses versu...

Selected issues related to the construction of the core chokes applied in sine wave filters were described in this paper. Comparison of test results and simulations of the impact of multi-gap core construction on the losses and acoustic field around the filter were presented. The tests were performed for the sine wave FluxSIN type filter. Simulatio...

Microstructure and magnetic properties of the $({rm Fe}_{x}{rm Co}_{1})_{76}{rm Mo}_{8}{rm Cu}_{1}{rm B}_{15}$ amorphous metallic alloys ( $x={3}$ , 6, and 9) are investigated by macroscopic magnetic measurements as well as a local probe technique. The microstructure of alloys is described using the findings from Mössbauer spectrometry. Study of ma...

Examination of microstructure and magnetic properties of amorphous (Fe$_{1}$ Co$_{\rm x}$)$_{79}$ Mo$_{8}$ Cu$_{1}$ B$_{12}$ alloys (${\rm x} = 1, 2$ and $3$) are performed by combination of analytical techniques. Chemical composition of the investigated samples was tested by laser induced breakdown spectroscopy (LIBS). Mössbauer spectroscopy and X...

The microstructure and magnetic properties of Fe82Zr 4Nb3B10Cu1, Fe80Zr 4Mn3B12Cu1 and Fe 80Zr4Ti3Cu1B12 alloys were investigated. Using RALE software the basic parameters of transformers made from nanocrystalline alloys with about 25% and 50% of crystalline phase were calculated. The transformer made from Fe80Zr4Ti 3Cu1B12 alloys after annealing a...

This paper deals with the implementation of a new solution for a three-phase AC transformer with electromagnetic and electric coupling (hybrid coupling). The electromagnetic coupling is realized by means of the conventional three-phase transformer (TR) with two secondary windings in each phase. The electrical coupling is realized by means of a matr...

Structure relaxations and low-field magnetic properties of the thick amorphous Fe75-xAl5P11GaB4C5 (x=0, 2 or 5) ribbons subjected to accumulative annealing below the crystallization temperature are investigated. From Mössbauer spectroscopy studies we have found that the average hyperfine field slighty increases after the heat treatment of the sampl...

It has been found that the replacement of 50% of Fe atoms by Co atoms in the Fe83Nb3B13Cu1 amorphous alloy enhances the saturation magnetization. The presence of α-FeCo grains in the nanocrystalline Fe41.5Co41.5Nb3B13Cu1 alloy leads to higher magnetic susceptibility and saturation magnetization at elevated temperatures in comparison with the Fe83Nb...