scholarly journals Evaluation of frame-induced compressive stress on the magnetic properties of stator cores using the excitation inner core method

2018 ◽  
Vol 69 (6) ◽  
pp. 477-480
Author(s):  
Mohachiro Oka ◽  
Masato Enokizono
Keyword(s):  
Magnetic Properties ◽  
Compressive Stress ◽  
Inner Core ◽  
Iron Loss ◽  
Electric Motors ◽  
Stator Core ◽  
Core Method

Abstract To improve the efficiency of electric motors, we developed the excitation inner core method to evaluate the magnetic properties such as the iron loss of the actual stator core. After preparing two stator cores with a frame, we examined the frames influence of compressive stress by applying the standard and small excitation inner core methods to evaluate the iron loss of both stator cores having a frame. After removing the frames of the two stator cores, we evaluated the iron loss of two stator cores without the frames again by applying both methods.

scholarly journals Estimation of the Iron Loss in Deep-Sea Permanent Magnet Motors considering Seawater Compressive Stress

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yongxiang Xu ◽  
Yanyu Wei ◽  
Jibin Zou ◽  
Jianjun Li ◽  
Wenjuan Qi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Stress Distribution ◽  
Permanent Magnet ◽  
Compressive Stress ◽  
Deep Sea ◽  
Iron Loss ◽  
Permanent Magnet Motors ◽  
Stator Core ◽  
Land Type ◽  
Type Motor

Deep-sea permanent magnet motor equipped with fluid compensated pressure-tolerant system is compressed by the high pressure fluid both outside and inside. The induced stress distribution in stator core is significantly different from that in land type motor. Its effect on the magnetic properties of stator core is important for deep-sea motor designers but seldom reported. In this paper, the stress distribution in stator core, regarding the seawater compressive stress, is calculated by 2D finite element method (FEM). The effect of compressive stress on magnetic properties of electrical steel sheet, that is, permeability, BH curves, and BW curves, is also measured. Then, based on the measured magnetic properties and calculated stress distribution, the stator iron loss is estimated by stress-electromagnetics-coupling FEM. At last the estimation is verified by experiment. Both the calculated and measured results show that stator iron loss increases obviously with the seawater compressive stress.

scholarly journals Magnetic properties of silicon steel sheet core with different processing stress

2018 ◽  
Vol 207 ◽  
pp. 03017
Author(s):  
Toshiki Matsui ◽  
Kyyoul Yun
Keyword(s):  
Magnetic Properties ◽  
Steel Sheet ◽  
Silicon Steel ◽  
Iron Loss ◽  
Stator Core ◽  
Steel Sheets ◽  
Shrink Fitting ◽  
Wire Cutting ◽  
Rotor Core ◽  
Processing Stress

The motor core including a rotor core and a stator core, which is made from silicon steel sheets. Iron loss increases during fixation of the stator core, e.g., by interlocking, welding, and shrink fitting installation. In this paper, the magnetic properties changes by each processing such as wire cutting, punching, interlocking and shrink fitting are investigated. Iron loss of the toroidal cores using punching, interlocking and shrink fitting are increased from 1.16 W/kg to 1.56 W/kg (34.4 % increased) at 50Hz, and from 21.1 W/kg to 27.5 W/kg (30.3 % increased) at 400 Hz compared with iron loss of wire cut toroidal core.

Evaluation of the Iron Loss of the Actual Stator Core to Achieve High Efficiency of the Rotating Machine

2010 ◽  
Vol 670 ◽  
pp. 447-454 ◽  
Author(s):  
Mohachiro Oka ◽  
Tugunori Kanada ◽  
Takayuki Kai ◽  
Masato Enokizono
Keyword(s):  
Manufacturing Process ◽  
Path Length ◽  
High Efficiency ◽  
Inner Core ◽  
Complex Configuration ◽  
Iron Loss ◽  
Stator Core ◽  
Rotating Machine ◽  
Iron Losses ◽  
Before And After

In this paper, the iron loss of an actual stator core of the complex configuration was evaluated by using the proposed effective magnetic path length and the excitation inner core, which were developed in this research. The iron loss of an actual stator core in the manufacturing process was described. Iron losses of actual stator cores before and after the varnish processing were measured using the excitation inner core of several kinds of shapes. As a result, iron losses of actual stator cores evaluated using the proposed effective magnetic path length were within appropriate values.

Evaluation of the Iron Loss Distribution of the Actual Stator Core Using Small Excitation Inner Cores

2012 ◽  
Vol 721 ◽  
pp. 90-95 ◽  
Author(s):  
Mohachiro Oka ◽  
Shimada Kazunori ◽  
Kawano Makoto ◽  
Masato Enokizono
Keyword(s):  
Inner Core ◽  
Complex Structure ◽  
Iron Loss ◽  
Manufacturing Processes ◽  
Stator Core ◽  
Loss Distribution ◽  
Rotating Machine ◽  
Iron Losses ◽  
Shrink Fitting ◽  
The Difference

To obtain the basic data to manufacture the highly effective rotating machine, the axial iron loss distribution of an actual stator core of the complex structure was evaluated by using the small excitation inner core. The laminated thickness of this small excitation inner core is approximately 1/6 of the thickness of the stator core. Therefore, the circumferential iron loss distribution of the stator core and the axial iron loss distribution of a stator core can be measured by using this small excitation inner core. Then, to compare the difference of the axial iron loss distribution in the stator core, we investigated the axial iron loss distribution in the actual stator core after two manufacturing processes, the laminating process and the shrink fitting process. The iron losses were measured in three places (the edge, the quarter part, and the center) of two stator cores. As a result of our investigation, the axial iron loss distribution in the actual stator core clearly changed. This paper reports on the axial iron loss distribution in two manufacturing processes in two actual stator cores measured by using the small excitation inner core.

Measuring Iron Loss of the Electrical Steel Sheets with Different Grades under Compressive Stress Normal to the Surface

2019 ◽  
Vol 139 (4) ◽  
pp. 190-196
Author(s):  
Shinya Urata ◽  
Yoshitaka Maeda ◽  
Hideo Nakai ◽  
Yuuya Takeuchi ◽  
Kyyoul Yun ◽  
...  
Keyword(s):  
Compressive Stress ◽  
Electrical Steel ◽  
Iron Loss ◽  
Steel Sheets ◽  
Electrical Steel Sheets

scholarly journals Analytical Iron Loss Evaluation in the Stator Yoke of Slotless Surface-Mounted PM Machines

2021 ◽  
Author(s):  
Matteo Leandro ◽  
Nada Elloumi ◽  
Alberto Tessarolo ◽  
Jonas Kristiansen Nøland
Keyword(s):  
Core Loss ◽  
Lookup Table ◽  
Iron Loss ◽  
Estimation Methods ◽  
Design Stage ◽  
Loss Assessment ◽  
Stator Core ◽  
Element Analysis ◽  
Field Solution ◽  
Loss Models

<div>One of the attractive benefits of slotless machines is low losses at high speeds, which could be emphasized by a careful stator core loss assessment, potentially available already at the pre-design stage. Unfortunately, mainstream iron loss estimation methods are typically implemented in the finite element analysis (FEA) environment with a constant-coefficients dummy model, leading to weak extrapolations with huge errors. In this paper, an analytical method for iron loss prediction in the stator core of slotless PM machines is derived. It is based on the extension of the 2-D field solution over the entire machine geometry. Then, the analytical solution is combined with variable- or constant-coefficient loss models (i.e., VARCO or CCM), which can be efficiently computed by vectorized post-processing. VARCO loss models are shown to be preferred at a general level.Moreover, the paper proposes a lookup-table-based (LUT) solution as an alternative approach. The main contribution lies in the numerical link between the analytical field solution and the iron loss estimate, with the aid of a code implementation of the proposed methodology. First, the models are compared against a sufficiently dense dataset available from laminations manufacturer for validation purposes. Then, all the methods are compared for the slotless machine case. Finally, the models are applied to a real case study and validated experimentally.</div>

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