Relationship among eddy current loss, frequency, maximum flux density and a new parameter concerning the number of domain walls in polycrystalline and amorphous soft magnetic materials

1981 ◽  
Vol 17 (4) ◽  
pp. 1478-1480 ◽  
Author(s):  
Yo Sakaki ◽  
S. Imagi
Keyword(s):  
Magnetic Materials ◽  
Flux Density ◽  
Eddy Current ◽  
Domain Walls ◽  
Eddy Current Loss ◽  
Soft Magnetic Materials ◽  
Soft Magnetic ◽  
Current Loss ◽  
Maximum Flux ◽  
Frequency Maximum

Utilization of Reluctance Electromagnetic Force of Inner-Mover-Type Rotary-Linear Motor

2020 ◽  
Vol 14 (1) ◽  
pp. 129-134
Author(s):  
Fumiaki Osawa ◽  
Keyword(s):  
Magnetic Materials ◽  
Eddy Current ◽  
High Power ◽  
Electromagnetic Force ◽  
Eddy Current Loss ◽  
Soft Magnetic Materials ◽  
Direct Drive ◽  
Soft Magnetic ◽  
Salient Pole ◽  
Three Phase

A multiple-degree-of-freedom (multi-DOF) motor can constitute small-sized and lightweight systems capable of performing complicated motions. Furthermore, the prospects for applications to industrial instruments via a direct drive are promising. This study aimed to develop practical multi-DOF motors capable of performing high-power rotary and linear motions using conventional three-phase inverters. A motor that performs rotary and linear motions is proposed. First, a method is presented for installing a salient pole on a needle with magnets. The method facilitates the use of soft magnetic materials with low eddy-current loss as iron cores. This study demonstrated the effectiveness of the salient pole for increasing the electromagnetic force. The model is used to explain the interactive magnetic interference generated by the armature currents for rotational and translation motions.

A General Coercivity Model for Soft Magnetic Materials

2012 ◽  
Vol 727-728 ◽  
pp. 157-162 ◽  
Author(s):  
Marcos Flavio de Campos
Keyword(s):  
Grain Size ◽  
Energy Balance ◽  
Magnetic Materials ◽  
Domain Walls ◽  
Soft Magnetic Materials ◽  
Force Balance ◽  
Balance Model ◽  
Soft Magnetic ◽  
Crystalline Defects ◽  
Magnetostatic Energy

The effect of crystalline imperfections (as for instance, grain size, inclusions and dislocations) on the coercivity of soft magnetic materials is additive. This only can be explained by an Energy Balance Model. By another hand, the angular dependence of the coercivity only can be explained with a Force Balance Model. Thus both models, Energy Balance and Force Balance have to be invoked for the construction of a general model. The effect of dislocations on the coercivity can be treated as short range magnetostrictive effect. The effect of inclusions needs the consideration of the global magnetostatic energy of the system. The dependence of the coercivity with the grain size can also be explained analyzing the magnetostatic energy. The idea of pinning of domain walls by crystalline defects is reformulated, and it is shown that the coercivity increase due to crystalline defects is principally caused by variations of the magnetostatic energy in the system.

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