Dynamic hysteresis modeling of silicon steel sheet considering excess eddy-current loss

The active magnetic bearing (AMB) is a new kind of high-performance bearing which suspends the rotor with controlled electromagnetic force. It was chosen to support the rotor of the helium blower in HTR-PM instead of conventional bearings. The power losses in the active magnetic bearings compose of three components: copper loss, iron loss and windage loss. In this paper, the iron loss, which composes of the eddy current loss and the hysteresis loss, is researched. The power loss of silicon steel lamination (35H300) was measured. Experimental data was taken over a range of 50Hz to 25,000Hz (sinusoidal current) for several magnetic field intensities. According to the experimental data, the eddy current loss and hysteresis loss increase with the frequency. And the hysteresis loss in the silicon steel lamination occupies the major part when the frequency of current is low, however the growth rate of eddy current is much faster than that of the hysteresis loss. And the FEM calculation of power loss in the magnetic bearing, which rotor and stator are made from silicon steel lamination (35H300), is also presented. The result shows the core loss of magnetic bearing also follow the separation theory. We can separate the core loss of magnetic bearing into two parts: hysteresis loss and eddy current loss. It will be very useful to calculate the power loss in the magnetic bearing.

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Performance analysis of magnetic gear with Halbach array for high power and high speed

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209410 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 959-967

Author(s):

Se-Yeong Kim ◽

Tae-Woo Lee ◽

Yon-Do Chun ◽

Do-Kwan Hong

Keyword(s):

Permanent Magnet ◽

Eddy Current ◽

High Power ◽

High Speed ◽

Torque Ripple ◽

Eddy Current Loss ◽

Element Analysis ◽

Current Loss ◽

Halbach Array ◽

Magnetic Gear

In this study, we propose a non-contact 80 kW, 60,000 rpm coaxial magnetic gear (CMG) model for high speed and high power applications. Two models with the same power but different radial and axial sizes were optimized using response surface methodology. Both models employed a Halbach array to increase torque. Also, an edge fillet was applied to the radial magnetized permanent magnet to reduce torque ripple, and an axial gap was applied to the permanent magnet with a radial gap to reduce eddy current loss. The models were analyzed using 2-D and 3-D finite element analysis. The torque, torque ripple and eddy current loss were compared in both models according to the materials used, including Sm2Co17, NdFeBs (N42SH, N48SH). Also, the structural stability of the pole piece structure was investigated by forced vibration analysis. Critical speed results from rotordynamics analysis are also presented.

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Development of Interior Permanent Magnet Motors with Concentrated Windings for Reducing Magnet Eddy Current Loss

IEEJ Transactions on Industry Applications ◽

10.1541/ieejias.129.1022 ◽

2009 ◽

Vol 129 (11) ◽

pp. 1022-1029 ◽

Cited By ~ 3

Author(s):

Katsumi Yamazaki ◽

Yuji Kanou ◽

Yu Fukushima ◽

Shunji Ohki ◽

Akira Nezu ◽

...

Keyword(s):

Permanent Magnet ◽

Eddy Current ◽

Eddy Current Loss ◽

Permanent Magnet Motors ◽

Current Loss ◽

Interior Permanent Magnet

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Helical retaining sleeve for eddy current loss reduction in high-speed SPM machine

Electrical Engineering ◽

10.1007/s00202-021-01218-4 ◽

2021 ◽

Author(s):

Mahir Al-ani ◽

Simon Barrans

Keyword(s):

Eddy Current ◽

High Speed ◽

Eddy Current Loss ◽

Loss Reduction ◽

Current Loss

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Eddy Current Loss in Grain-Oriented Steel Laminations due to Normal Leakage Flux

IEEE Transactions on Magnetics ◽

10.1109/tmag.2021.3069727 ◽

2021 ◽

pp. 1-1

Author(s):

Wei Wang ◽

Arne Nysveen ◽

Niklas Magnusson

Keyword(s):

Eddy Current ◽

Eddy Current Loss ◽

Current Loss ◽

Leakage Flux

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An Alternative Method for Calculating the Eddy Current Loss in the Sleeve of a Sealless Pump

Actuators ◽

10.3390/act10040078 ◽

2021 ◽

Vol 10 (4) ◽

pp. 78

Author(s):

Tomislav Strinić ◽

Bianca Wex ◽

Gerald Jungmayr ◽

Thomas Stallinger ◽

Jörg Frevert ◽

...

Keyword(s):

Eddy Current ◽

Three Dimensional ◽

Eddy Current Loss ◽

Theoretical Background ◽

Air Gap ◽

Magnetic Flux Density ◽

Pump Impeller ◽

Current Loss ◽

Faraday’S Law ◽

Transient Simulations

A sealless pump, also known as a wet rotor pump or a canned pump, requires a stationary sleeve in the air gap to protect the stator from a medium that flows around the rotor and the pump impeller. Since the sleeve is typically made from a non-magnetic electrically conductive material, the time-varying magnetic flux density in the air gap creates an eddy current loss in the sleeve. Precise assessment of this loss is crucial for the design of the pump. This paper presents a method for calculating the eddy current loss in such sleeves by using only a two-dimensional (2D) finite element method (FEM) solver. The basic idea is to use the similar structure of Ampère’s circuital law and Faraday’s law of induction to solve eddy current problems with a magnetostatic solver. The theoretical background behind the proposed method is explained and applied to the sleeve of a sealless pump. Finally, the results obtained by a 2D FEM approach are verified by three-dimensional FEM transient simulations.

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