Statistical Loss Model Research Articles

Prediction of the Energy Losses in Soft Magnetic Alloys Based on the Magnetic Objects Theory in the Case of the Uniform Magnetic Flux Penetration

We report an investigation and a theoretical assessment of energy loss prediction in crystalline and amorphous soft magnetic materials. There were tested a sample made from non-oriented silicon iron (NO FeSi) M800-65A, industrial type alloy, cut longitudinally to the rolling direction and a toroidal sample of Co67Fe4B14.5Si14.5 amorphous ribbon. The losses behaviour of the crystalline NO FeSi strip was studied as function of frequency in the range of 5 Hz to 200 Hz at a given magnetic polarization (Jp) of 0.5 T and 1 T. In the case of the amorphous Co-based ribbon the losses variation was studied as function of frequency in the range of 5 Hz to 10 kHz at a given magnetic polarization of 20 mT. Using the concept of loss separation for the data analysis, in the approximation of linear magnetization law and low frequency limit, it can be considered in both cases, that the excess losses can be quantitatively assessed within the theoretical framework of the statistical loss model based on magnetic object theory.

A Specific Magnetic Losses Calculation in Non Oriented Electrical Steel Laminations

The paper intends to study the magnetic losses of non-oriented electrical steel laminations under sinusoidal voltage supply. The measurement of magnetic losses of electrical steel laminations in Epstein Frame is implemented step by step at frequency range from 50 Hz. The calculation of the magnetic losses is made by using two methods based on the statistical loss model. Our contribution consists on the first model which corresponds to the curve fitting method which needs many experimental data but allows a better exactitude. The second method is defined in a time domain, in order to account of the presence of harmonics in the flux density wave form. The coefficients of the second method are determined from the curve fitting. A good agreement between practice and theory was established with these two methods

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.

Predicting Loss in Magnetic Steels Under Arbitrary Induction Waveform and With Minor Hysteresis Loops

We have studied ways of predicting power losses in soft magnetic laminations for generic time dependence of the periodic magnetic polarization J(t). We found that, whatever the frequency and the induction waveform, the loss behavior can be quantitatively assessed within the theoretical framework of the statistical loss model. The prediction requires a limited set of preemptive experimental data, depending on whether or not the arbitrary J(t) waveform is endowed with local slope inversions (i.e., minor hysteresis loops) in its periodic time behavior. In the absence of minor loops, such data reduce, for any peak polarization value J/sub p/, to the loss figures obtained under sinusoidal J(t) at two different frequency values. In the presence of minor loops of semiamplitude J/sub m/, the two-frequency loss experiment should be carried out for both peak polarization values J/sub p/ and J/sub m/. Additional knowledge of the quasi-static major loop, to be used for modeling hysteresis loss, does improve the accuracy of the prediction method. A more general approach to loss in soft magnetic laminations is obtained in this way, the only limitation apparently being the onset of skin effect at high frequencies.

Minimum force model. Effect of crystallographic texture on the magnetostriction and loss characteristics of non-oriented electrical steels

The internal coercive field has been associated with the minimum force counteracting the motion of 180° Bloch walls, which depends on the relative orientation between the crystal axes and the magnetisation direction. The minimum force is related both to the texture-dependent components of the hysteresis loss and to the internal coercive field derived from the statistical loss model by Bertotti. Correlations have been also found with the fitting parameters of a previously presented magnetostriction model.