Wojciech Pluta

Some Properties of Factors of Specific Total Loss Components in Electrical Steel

One of the most important parameters of electrical steel sheet is specific total loss. In order to analyze the specific total loss, seven electrical steel grades were separated into three components: the hysteresis loss component and both the classical and additional eddy current loss components. Parameters used for the description of loss components in statistical loss models were analyzed and found to be dependent on electrical steel grade, and hence, on grain orientation. The aim of this paper is to provide a contribution to the better understanding of magnetic specific total loss in electrical steel sheets.

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.

Specific Total Loss Components Under Axial Magnetization in Electrical Steel Sheets With Different Degree of Goss Texture

Electrical steel sheets (ESS) play an important role in the magnetic circuit core design of electrical machines. One of the most obvious parameters of these machines is their efficiency which depends mainly on total core loss. Hence, it depends on the ESS quality which is graded according to specific total loss (PS). Several years ago PS was measured at peak magnetic flux density equal to 1.0 T, later at 1.5 T, and presently the value of 1.7 T is used for classification. This increase from 1.0 to 1.7 T results from both material and instrumentation improvements. According to present knowledge, the PS of ESS consists of three components: a hysteresis loss component and both classical and additional eddy current loss components. It was found that all three components are dependent on anisotropy, i.e. the degree of Goss texture. These dependencies, however, show different trends as the magnetic flux density increases. The aim of this paper is to make a contribution to a better understanding of specific total loss in ESS with different degrees of Goss texture.

Calculating power loss in electrical steel taking into account magnetic anisotropy

Study of anisotropic properties of specific total power loss under axial magnetization and at different frequencies was carried out using a non-standard SST apparatus. Analysis of the relationship between hysteresis components, additional eddy current and magnetic anisotropy justifies considering these components together. The purpose of this article is to propose a method for calculating power losses taking into account the phenomenon of magnetic anisotropy and the magnetizing frequency. (Obliczanie strat mocy w blachach elektrotechnicznych z uwzględnieniem anizotropii magnetycznej). Słowa kluczowe: składowe stratności, anizotropia magnetyczna, blacha elektrotechniczna.

Angular Properties of Specific Total Loss Components Under Axial Magnetization in Grain-Oriented Electrical Steel

Electrical steel (ES) plays an important role in the design of magnetic circuit cores of electrical machines. Separating specific total loss into components is an excellent tool for loss analysis in ES. As is commonly accepted, the specific total loss is separated into three components: hysteresis and both classical and additional eddy current loss components. In addition, the conventional grain-oriented (GO) ES presents the strong anisotropy of magnetic properties, due to the (110) [001] Goss texture, with [001] the easiest direction [parallel to rolling direction (RD)], with intermediate [011] and magnetically worst [111] directions, at angles x = 0°, 90°, and about 54° to RD, respectively. However, magnetization angles 0° <; x <; 54° and 54° <; x <; 90° also play a very important role in the research of specific total loss components. The angular properties of specific total loss under axial magnetization in GO ES should be most preferably evaluated by the use of single-sheet tester with specimens cut at different angles with respect to RD. This paper demonstrates, in the quantitative way, the dependence of hysteresis Ph and additional eddy current Pa specific total loss components on Goss texture. In addition, the results obtained justify the division of specific total loss and its components in two flux density regions: below Bm ≤ 1 T (the lower region) and above Bm > 1 T (the upper region). This paper is intended to offer a better understanding of phenomena that cause magnetic anisotropy, i.e., different Goss textures.

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.

Influence of Anisotropy on Specific Loss Components in Grain Oriented Electrical Steel

Electrical steel sheets play an important role in magnetic circuit core design of electrical machines. Electrical steel are graded depending on value of specific total loss (PS). According to the present knowledge the PS loss consists of three components: hysteresis loss and both classical and additional eddy current loss components. Magnetic properties depend on direction of magnetization i.e. magnetocrystalline anisotropy. The determination of the specific power loss separation of electrical steel sheets in different direction to rolling direction have been performed using non-standard single sheet tester. Specific total loss was separated into hysteresis, eddy current and excess loss components. The relationship between the hysteresis and additional loss components and the magnetic anisotropy was analyzed. The aim of this paper is to provide a contribution to the better understanding of specific total loss in electrical steel with Goss texture.

Measurement of some magnetic properties of electrical steel sheets under axial magnetization

Improvement in properties of electrical machines can be obtained by proper design which requires precise simulation and knowledge about properties of used magnetic materials. One very important property is specific power loss. To analyze, the specific power loss of electrical steel is helpful to separate the loss into three components. It is commonly accepted that the specific power loss consists of three components: hysteresis loss component and both classical and additional eddy current loss components. All three components are dependent on degree of texture and show different trends as the magnetic flux density increases. The aim of the paper is to provide a contribution to the better understanding of magnetic specific power loss in electrical steel sheets with different degree of Goss texture.

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.