Core Loss Behavior Research Articles

Core-loss behavior of Fe-based nanocrystalline at high frequency and high temperature

Core-loss behavior of Fe-based nanocrystalline at high frequency and high temperature

Influence of compressive stress on the magnetic characteristics of grain-oriented material under non-sinusoidal excitation

Electric machines are subjected to mechanical stress during their operation, which significantly affects the magnetic characteristics of the core material. Furthermore, as the converter topologies evolve, the induced harmonic content increases. The analysis of magnetic properties due to both magnetomechanical effects and harmonics is rarely addressed. This work provides a deeper insight into the core loss behavior by analyzing the impact of mechanical stress on the hysteresis characteristics of magnetic materials subjected to non-sinusoidal excitation. A qualitative analysis based on the measured characteristics is presented to study the material behavior under sinusoidal and non-sinusoidal excitations. An analytical approach based on the Lavers’ formula and loss separation theory is presented.

Magnetic core loss behavior at high fields in magnetic materials

Magnetic core loss behavior at high fields in magnetic materials

Magnetic Properties and Core Loss Behavior of Fe-6.5wt.%Si Ribbons Prepared by Melt Spinning

Fe-6.5wt.%Si alloy is prepared in the form of continuous ribbons with 25 mm in width and 0.03 mm in thickness by using melt spinning technique. The ribbons are flexible and could be wounded into tapes. DC magnetic properties and core loss behaviors of the ribbons after heat treatment are investigated in this paper. The magnetic properties are compared with ribbons by cold rolling and CVD methods. The melt spinning ribbons exhibit much less core loss in the frequencies more than 10 kHz. The melt spinning ribbons are promising to be used for electric devices used in medium or higher frequencies.

AC Magnetic Properties and Core Loss Behavior of Fe–P Soft Magnetic Sheets

AC magnetic properties and core loss behavior of differently prepared Fe-P sheets have been analyzed in this paper. Furthermore, the results have been compared with non-oriented silicon (Si) steel. The coercivity, magnetic flux density, and permeability measurements in dc magnetic field show Fe-P has better soft magnetic properties than Si steel. The ac magnetic behavior of both the samples has been studied in the frequency range from dc to 1 kHz for a range of flux density values. The above studies indicate that crystalline Fe-P alloys can be the replacement of so-called Si steel for low-power device applications.

Core loss behavior in high frequency high power transformers—I: Effect of core topology

This two-part paper presents an overview of core loss computations performed in both time and frequency domains in order to evaluate their behavior in single phase transformers with different core topologies. Moreover, the effects of non-sinusoidal waveforms on well-known core loss calculation methods are investigated with both analytically and finite element calculations. Three well-known configurations of transformers utilized in high frequency high power applications are investigated, namely, the core type, the shell type, and the matrix transformer. Based on the results obtained from a large number of FEM simulations for different operating conditions, the efficiencies of the transformers are compared in terms of distribution of magnetic flux density, loss density, total core loss, and weight. The analysis shows that for lower range of frequency and power, the shell type core could be the favorable option, and on the other hand, core type seems to be an appropriate solution for higher values of the operating frequency and nominal power.

Core loss behavior in high frequency high power transformers—II: Arbitrary excitation

High frequency high power transformers used in power electronic converters are frequently subjected to non-sinusoidal excitations. The main purpose of this paper is to study the effects of some general arbitrary waveforms on magnetic core loss in these transformers. First, using well-known empirical equations, general expressions were derived based on the parameters of the waveforms. Second, the impacts of different orders of voltage harmonics were investigated. Finally, capabilities of nanocrystalline and amorphous magnetic materials were compared. It is shown that the loss inside the core is highly sensitive to the rise time and duty cycle of trapezoidal and rectangular waveforms, respectively. Furthermore, although amorphous materials have higher saturation flux density, the total core loss inside the transformer designed using nanocrystalline material is considerably lower than the similar transformer with amorphous materials.

Behavior of Core Loss in Nanocrystalline Fe73.5Cu1Nb3Si13.5B9 Alloy with High Br

In the ranges of f=1020000Hz and Bm=0.11.0T, the core loss has been measured for nanocrystalline Fe73.5Cu1Nb3Si13.5B9 alloy with high Br. The total power loss was decomposed into the sum of the classical eddy current loss, the hysteresis loss and the excess loss. The results show that the change of the total loss per cycle with frequency clearly shows a nonlinear behavior, which has been described in terms of Bertotti's statistical theory of loss. The frequency range examined can nearly be divided into two intervals, in which there exist two different describing ways.

Magnetomechanical resonant losses in metallic glasses

Excess core losses, attributable to mechanical resonances, are observed in tape-wound toroidal cores of two Fe-rich metallic glasses. In the absence of these resonances, the behavior of core loss as a function of frequency follows traditional models. The damping of the mechanical resonances is described in this paper. The reduction of the resonance losses is identified as due to externally supplied viscous damping forces.

Influence of the macrostructure of thin grain-oriented 3% Si-Fe ribbons on the core loss behavior under stress

It is shown that the total core loss of thin grain-oriented 3% Si-Fe ribbons is optimal at sharp {110} 〈001〉 texture and at suitable grain size. The elastic tensile stress reduces significantly the power loss of these sharply textured materials both at small and large grain sizes.