Viatcheslav Permiakov

Measuring setup for the investigation of the influence of mechanical stresses on magnetic properties of electrical steel

An experimental setup is discussed allowing measurement of the magnetic properties at any angle between the magnetic flux and applied tensile stress. The magnetic measurements are performed locally by means of needles and H-coils. Some preliminary results for a unidirectional flux under different values of tensile stresses are presented.

Dependence of power losses on tensile stress for Fe–Si nonoriented steel up to destruction

The study of the influence of mechanical stress on magnetic properties of laminated steel is the subject of recent research. In this article the separation of losses is performed and the dependence of total, hysteresis, and excess losses on tensile stress up to destruction is investigated. With increasing of tensile stress, the total and hysteresis losses are first decreasing and then increasing at higher stress. The increase of total losses was found mainly due to the hysteresis losses while the classical and excess components influence the total power losses to a minor extent. For extensive deformation the increase of losses becomes dramatically high.

Rotational magnetization in nonoriented Fe-Si steel under uniaxial compressive and tensile stresses

The influence of uniaxial mechanical stress on the magnetization processes and energy losses in nonoriented Fe-Si steels is investigated under alternating and circular rotational flux. The advanced waveform control and measurement technique allow creating any kind of magnetic flux from alternating in all directions to different elliptical and circular rotational flux. The study of rotational magnetization under uniaxial stress gives a new perspective on the change of anisotropy of the material due to applied compressive or tensile stresses, as well as plastic deformation. Due to the broad use of nonoriented steel under rotational magnetization and mechanical stress or deformation, the new study could have a wide practical application.

Modelling of electromagnetic losses in asynchronous machines

This paper deals with the numerical modelling of electromagnetic losses in electrical machines, using electromagnetic field computations, combined with advanced material characterisations. The paper gradually proceeds to the actual reasons why the building factor, defined as the ratio of the measured iron losses in the machine and the losses obtained under standard conditions, exceeds the value of 1.

Preisach modeling of magnetization and magnetostriction processes in laminated SiFe alloys

In this article, magnetization loops under mechanical stress and magnetostriction loops under quasistatic magnetic excitation conditions are discussed. In both cases, the hysteresis loops are modeled using the Preisach theory. The identification procedure of the material parameters is described. The article discusses first the shape of the Preisach distribution function for the study of magnetostriction loops. Next, a Preisach model is proposed for the description of magnetization loops under mechanical stress starting from the magnetization loop obtained without applying mechanical stress. A setup has been constructed for the measurement of magnetization loops under compressive or tensile stress. Also, a measuring system based on a single sheet tester and on optical displacement measurement techniques is used to establish the magnetostrictive behavior of laminated SiFe alloys. It is shown that a good correspondence between the calculated and measured magnetization and magnetostriction loops is obtained.

Investigation of residual effects of tensile stress on magnetic properties of non-oriented electrical steel

In this paper, a procedure which allows magnetic measurements in different directions with respect to the direction of the applied stress is described. Experimental data on a nonoriented electrical steel is presented. The magnetic properties in different directions were determined as a function of mechanical tensile stress. The impact of the residual effects of tensile stress on the magnetic properties of nonoriented electrical steel is considered.

Measurement Techniques for Magnetic Characterization of Fe-Si Alloys

Standard measurements techniques for magnetic characterization of Fe-Si steels are agreed upon in IEC 60404-2 and IEC 60404-3. Unfortunately, the standard methods are not capable to characterize the behaviour of magnetic materials under various complex magnetomechanical conditions, such as rotational magnetization, compressive and tensile stresses and plastic strains. Based on the standard measurement techniques, a more complex magnetic characterization of Fe-Si alloys at different conditions can be developed for better understanding of energy loss, and generally, energy conversion in electromagnetic devices. In this work, recent achievements in the methodical characterization of Fe-Si alloys at various combinations of magnetic conditions at externally applied uniaxial mechnical load are described

Microstructural study of dependence of magnetic properties of nonoriented electrical steel on applied mechanical load

In this paper, the dependence of the magnetic properties of electrical steel on the applied mechanical load is investigated on basis of the microstructural analysis. The special setup was used in the current investigation that allows carrying out the magnetic measurements under applied tensile stress up to destruction of the sample.