Marian Soinski

Apparent core losses and core losses in five-limb amorphous transformer of 160 kVA

Significant modifications of the shape of magnetic flux in columns and yokes were observed in the magnetic circuit of four amorphous cores used in a 3-phase transformer. The magnetic losses measured experimentally were significantly higher than the ones calculated theoretically. The values quoted in this paper were obtained in our study, and they are indicative of the need of taking them into consideration when designing 5-limb amorphous distribution transformers.

Metrological attributes of current transformers in electrical energy meters

Instrument current and voltage transformers remain the basic apparatus used in measurements of energy in electri- cal grid. Increasing importance of distributed energy sources necessitates more precise measurements of consumed as well as generated electrical energy. Both types occur in low voltage network where the main focus is on current transformers for electronic-type electrical energy meters. These current transformers should fulfil many requirements for precise electri- cal energy measurements. This paper presents a modern system for measurement of various metrological features of current transformers.

Nanocrystalline Block Cores for High-Frequency Chokes

Nanocrystalline Fe-based soft magnetic materials are more and more common not only in power electronic, but also in power energy conversion systems. The use of different treatments (the methods of stacking and annealing at/without magnetic field presence) on magnetic cores allow to achieve their predefined magnetic properties. This fact increases the level of the applicability such magnetic cores. Different concepts of nanocrystalline magnetic block cores were discussed in this paper. Obtained results were compared with magnetic cores used up to nowadays (made of amorphous and Fe-Si steel).

Anisotropy of DC magnetostriction in cold-rolled electrical sheets of Goss texture

The maximum differences are found to exist between the directions [100] and [110], and not between [100] and [111]. A similar relation occurs also for the coercive force. Anisotropy of magnetostriction is brought about by the sheet crystalline structure and texture. The phenomenon has been analyzed qualitatively. It was found that the elongation depended on the magnetic flux direction and the degree of texture. >

Anisotropy of demagnetization in rectangular electrical sheet samples placed in a stationary magnetic field

The method of summation used for calculating magnetic field distribution was applied to determine the anisotropy of demagnetization of rectangular samples made of anisotropic and isotropic electrical sheets. The calculations refer to a standard strip used in an Epstein test and to the samples placed in homogeneous. external magnetic field. Changes in the demagnetization anisotropy were determined for different degrees of crystallographic orientation in the materials. In the case of electrical strip sheets, the results make it possible to determine the real B-H magnetization characteristic for the material, which is also very important in many cases for instrumentation. >

Anisotropy of magnetic properties in thin electrical sheets

Magnetic properties of thin electrical sheets of AN1 and AN3 types are described. Data on anisotropy of the coercive force determined from Epstein tests and from coercivemeter measurement (in an open magnetic circuit) anisotropy of magnetic induction in DC and AC magnetization conditions are presented. Anisotropy of core losses and degree of Goss texturing are also reported. >

Properties of Fe-based nanocrystalline magnetic powder cores (MPC) and structure of particle size distribution (PSD)

Abstract This paper discusses the influence of the Particle Size Distribution (PSD) of the nanocrystalline Fe-based granular-soft-magnetic material on the final magnetic properties of a Magnetic Powder Core (MPC). Here we show how PSD impacts the final magnetic properties. Mixing fine and coarse particles, with a dominance of coarse particles, significantly influences the magnetic permeability increase of the core. Better magnetic features are noted for MPCs constructed with certain mass ratio of fine and coarse particles due to improvement in the magnetic path in the cores. This allows to offer new induction components to industry.

Addressing an EMC Weakness Due to Strong Static Magnetic Fields

Strong stationary magnetic field from a permanent magnet, or strong electromagnetic field from many different sources, when used in a wrong way, can change a proper behavior in already optimized technical equipment. For example, many electronic electrical energy meters do not count correctly the consumption of electrical energy or low-voltage current transformers do not indicate proper level of output signal. This is the evidence of EM Compatibility lack. To prevent described situation from happen some actions have to be taken. The paper outlines the problem and proposes possible solution to the phenomenon of illegal using of the described EMC weakness.