scholarly journals Preliminary analysis of eddy current and iron loss in magnetic gear in electric vehicle

2022 ◽  
Vol 12 (2) ◽  
pp. 1161
Author(s):  
Mohd Firdaus Mohd Ab Halim ◽  
Erwan Sulaiman ◽  
Mahyuzie Jenal ◽  
Raja Nor Firdaus Kashfi Raja Othman ◽  
Syed Muhammad Naufal Syed Othman
Keyword(s):  
Electric Vehicle ◽  
Eddy Current ◽  
High Speed ◽  
High Energy ◽  
Gear Ratio ◽  
Eddy Current Loss ◽  
High Energy Density ◽  
Iron Loss ◽  
Current Loss ◽  
Magnetic Gear

The inclusion of a high energy density permanent magnet into magnetic gear improves the machine's torque density. However, it also contributes to eddy current loss, especially in a high-speed application such in electric vehicle. In this paper, the losses from eddy current and iron loss are investigated on concentric magnetic gear (CMG). Torque multiplier CMG is designed with 8/3 gear ratio for this study. Iron loss and eddy current loss are compared and discussed. Based on this study, eddy current loss contributes to almost 96% of the total loss. This finding is hoped to direct the researcher to focus more on reducing loss associated with eddy current loss.

Gear efficiency estimation method through finite element and curve fitting

2021 ◽  
pp. 1-19
Author(s):  
M.F.M.A. Halim ◽  
E. Sulaiman ◽  
R.N.F.K.R. Othman
Keyword(s):  
Finite Element ◽  
Eddy Current ◽  
Curve Fitting ◽  
High Energy ◽  
Gear Ratio ◽  
Eddy Current Loss ◽  
High Energy Density ◽  
Current Loss ◽  
Finite Element Software ◽  
Gear Efficiency

The inclusion of high energy density permanent magnet (PM) in MG contributes to the high eddy current loss in magnetic gear and reduces its efficiency. There was limited research done that focused on gear efficiency behavior over a broader range of speed and in different gear ratios. In this paper, the function of gear efficiency concerning gear ratio and rotational speed is proposed. Torque and eddy current loss data were obtained through transient magnetic analysis using finite element software at several rotational ranges and gear ratios. The analytical approach through mathematical substitution was discussed to confirm the finding in the simulation. The result showed that the gear efficiency decreases as the speed increases. Nonetheless, the gear efficiency revealed improvement in efficiency as the gear ratio increases. Finally, gear efficiency behavior was modeled using the curve fitting method. Subsequently, based on the correlation study, an equation was proposed, yielding a 1% error compared to the new simulated data. With this proposed method and equation, the analysis and estimation of gear efficiency behavior over wider speed and gear ratios are simplified, thus reducing the need to perform simulation over different speeds and gear ratios.

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

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.

Eddy current loss and its magnetization effect of electromagnetic buffer under intensive impact load

2020 ◽  
pp. 1-20
Author(s):  
Zixuan Li ◽  
Guolai Yang ◽  
Ning Liu
Keyword(s):  
Energy Density ◽  
Eddy Current ◽  
Impact Load ◽  
Current Model ◽  
High Energy ◽  
Eddy Current Loss ◽  
High Energy Density ◽  
Time Step ◽  
Current Loss ◽  
The Impact

In this paper, a high-energy density electromagnetic buffer (EMB) is studied and analysed for the violent acceleration and high velocity of intensive impact loads. First, the design requirements of the EMB are proposed to select reasonable structure and magnetic circuit parameters. The equivalent current model is used to introduce the primary eddy current affected by demagnetization effect and the induced secondary eddy current. The magnetization process is studied by dividing the conductor tube into the approach end and the departure end. Considering the nonlinear damping and eddy current interaction between primary and secondary, a primary-secondary eddy current loss coupled nonlinear time-step finite element model (FEM) is established to obtain the spatiotemporal distribution characteristics of eddy current. Finally, a test experiment with weak impact, medium impact and intensive impact was carried out. The measured displacement, velocity, damping force, and time nodes responses during buffering are consistent with the established time-step FEM results. The proposed high-energy density EMB can effectively complete the impact buffering process. It is reasonable to obtain the eddy current loss and its magnetization law from the established FEM which is suitable for shock buffering with different impulse strength.

Numerical analysis of eddy current loss of high-speed axial magnetic drive spindle

2021 ◽  
Vol 21 (2) ◽  
pp. 119
Author(s):  
Xu Qiao ◽  
Yang Tao ◽  
He Yuchen ◽  
Mei Shunqi ◽  
Meng Fanhe ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Eddy Current ◽  
High Speed ◽  
Eddy Current Loss ◽  
Current Loss ◽  
Magnetic Drive

Wireless Power Efficiency and Quality in Metal Shaft Environment With Eddy Current Losses and Electromagnetic Interference

2016 ◽  
Author(s):  
Miaomiao Xu ◽  
Xiongzhu Bu ◽  
Zhangjie Tu
Keyword(s):  
Eddy Current ◽  
Power Supply ◽  
Electromagnetic Interference ◽  
High Speed ◽  
Electromagnetic Coupling ◽  
Transmission Efficiency ◽  
Eddy Current Loss ◽  
Wireless Power ◽  
Current Loss ◽  
Wireless Power Supply

Wireless power transmission efficiency and ripple interference attract more and more attention nowadays, but in some special metal environments the transmission efficiency of wireless power will be greatly influenced. In some practical engineering application, we need to use wireless energy to power the sensor on the high speed rotating parts. In order to improve the transmission efficiency and quality of the wireless power supply, researches are conducted to evaluate the eddy current loss and electromagnetic interference of wireless power in high-speed rotating component parameter test system. In this paper, electromagnetic coupling wireless power supply system is established as the transmission model. Then the analytical expressions of eddy current loss are derived by solving Maxwell’s equations, and after that the eddy current loss characteristics is analyzed by combining with the electromagnetic coupling model and eddy current losses model in metal medium. To verify the theoretical results, Maxwell electromagnetic field simulation software is used to analyze the characteristics of the eddy current. Finally, experiments are carried out to illustrate the effect of ferrite magnetic shielding material on the eddy current loss and the shielding effect on the external electromagnetic interference in the metal shaft environment.

scholarly journals Reducing Rotor Temperature Rise in Concentrated Winding Motor by Using Magnetic Powder Mixed Resin Ring

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6721
Author(s):  
Mitsuhide Sato ◽  
Keigo Takazawa ◽  
Manabu Horiuchi ◽  
Ryoken Masuda ◽  
Ryo Yoshida ◽  
...  
Keyword(s):  
Eddy Current ◽  
Temperature Rise ◽  
High Speed ◽  
Eddy Current Loss ◽  
Magnetic Powder ◽  
Current Loss ◽  
Composite Ring ◽  
Spatial Harmonics ◽  
High Speed Rotation ◽  
Speed Rotation

The demand for high-speed servomotors is increasing, and minimal losses in both high-speed and high-torque regions are required. Copper loss reduction in permanent magnet motors can be achieved by configuring concentrated winding, but there are more spatial harmonics compared with distributed winding. At high-speed rotation, the eddy current loss of the rotor increases, and efficiency tends to decrease. Therefore, we propose a motor in which a composite ring made from resin material mixed with magnetic powder is mounted on the stator to suppress spatial harmonics. This paper describes three characteristic motor types, namely, open-slot motors, composite-ring motors, and closed-slot motors. Spatial harmonics are reduced significantly in composite-ring motors, and rotor eddy current loss is reduced by more than 50% compared with open-slot motors. Thermal analysis suggests that the saturation temperature rise value is reduced by more than 30 K. The use of a composite ring is effective in reducing magnet eddy current loss during high-speed rotation. Conversely, the torque characteristics in the closed-slot motor are greatly reduced as well as the efficiency. Magnetic circuits and simulations show that on electrical steel sheets with high relative permeability, the ring significantly reduces the torque flux passing through the stator, thus reducing the torque constant. To achieve reduced eddy current loss during high-speed rotation while ensuring torque characteristics with the composite ring, it is necessary to set the relative permeability and thickness of the composite ring according to motor specifications.

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