Fundamental-frequency eddy-current loss due to rotating magnetic field. Part 1: Eddy-current losses in solid rotors

1969 ◽  
Vol 116 (10) ◽  
pp. 1743
Author(s):  
R.A. Jamieson ◽  
K.P.P. Pillai
2018 ◽  
Vol 198 ◽  
pp. 04002 ◽  
Author(s):  
Zengyuan Yin ◽  
Yuanwen Cai ◽  
Weijie Wang ◽  
Yuan Ren

In order to reduce power losses for the aerospace applications, this paper analyzes the eddy current losses produced by high-speed rotating solid rotor core magnetic bearings of magnetically suspended control & sensitive gyroscope (MSCSG). An analytical model of the eddy current loss of a solid rotor radial magnetic bearing (RMB) is presented. Considering the difference between NNNN and NSNS magnetic circuits of RMB, the magnetic field expressions of stator magnetic poles are listed. The magnetic field of stator poles is replaced by Fourier series expansion. According to the magnetic field distribution around the magnetic pole surface and the boundary conditions of the rotor surface, the mathematical expression of eddy current loss is obtained. The measurement method of rotational power loss in radial magnetic bearing is proposed, and the results of the theoretical analysis are verified by experiments in the prototype MSCSG. The experimental results show the correctness of calculation results. Eddy current loss models and test methods provide theoretical support for analyzing eddy current losses in solid rotors and reducing power consumption.


2012 ◽  
Vol 468-471 ◽  
pp. 1086-1089 ◽  
Author(s):  
Yong Ming Xu ◽  
Chao Du ◽  
Da Wei Meng

The problem about the eddy current loss which is caused by leakage magnetic field in ultrahigh pressure large capacity power transformer is becoming more extrusive. It is very significant to research the power transformer leakage magnetic field and eddy current loss on the tank wall thoroughly and accurately. 3D finite element model of power transformer leakage magnetic field and eddy current loss is established in this paper, the eddy current loss on the tank wall is calculated and the distribution is analyzed. For the eddy current loss could be reduced by magnetic shielding, new calculation model are established respectively, then eddy current loss on tank wall could be got with shielding. The best size and location of the shielding could be analyzed after changing the height of the shielding, which provided the important evidence to reduce tank wall eddy current loss effectively. The calculating methods have been proved to be accuracy after experiment.


2017 ◽  
Vol 66 (2) ◽  
pp. 295-312 ◽  
Author(s):  
Hongbo Qiu ◽  
Wenfei Yu ◽  
Yonghui Li ◽  
Cunxiang Yang

AbstractAt present, the drivers with different control methods are used in most of permanent magnet synchronous motors (PMSM). A current outputted by a driver contains a large number of harmonics that will cause the PMSM torque ripple, winding heating and rotor temperature rise too large and so on. In this paper, in order to determine the influence of the current harmonics on the motor performance, different harmonic currents were injected into the motor armature. Firstly, in order to study the influence of the current harmonic on the motor magnetic field, a novel decoupling method of the motor magnetic field was proposed. On this basis, the difference of harmonic content in an air gap magnetic field was studied, and the influence of a harmonic current on the air gap flux density was obtained. Secondly, by comparing the fluctuation of the motor torque in the fundamental and different harmonic currents, the influence of harmonic on a motor torque ripple was determined. Then, the influence of different current harmonics on the eddy current loss of the motor was compared and analyzed, and the influence of the drive harmonic on the eddy current loss was obtained. Finally, by using a finite element method (FEM), the motor temperature distribution with different harmonics was obtained.


2013 ◽  
Vol 310 ◽  
pp. 262-265
Author(s):  
Xiao Peng Wu ◽  
Cheng Ning Zhang ◽  
Yu Gang Dong

The 2-D time-stepping finite element method is adopted to systematically analyze the effect of DC supply voltage of inverter on eddy current loss in permanent magnet of PMSM for EV application. The finite element model and inverter model are built to calculate the winding currents, eddy current losses in permanent magnet and air-gap flux densities with different DC supply voltages when the motor runs in flux-weakening area. Analysis shows that, the eddy current increases significantly with the increase of DC supply voltage, although the fundamental winding current decreases. The temperature-rise experiment of permanent magnet is carried out, proving the validity of analysis.


Author(s):  
Jinpeng Yu ◽  
Yan Zhou ◽  
Mo Ni ◽  
Guojun Yang ◽  
Lei Zhao

In the active magnetic bearing (AMB) system, the eddy current is generated during the rotation of the rotor, which brings about the AMB loss and eddy-current magnetic field. The eddy-current magnetic field will reduce the electromagnetic force and generate the resistance torque of the AMB. Basing on the AMB of the Primary Helium Circulator (PHC) in HTR-PM, two-dimensional (2D) and three-dimensional (3D) AMB models are built and analyzed with finite element analysis (FEA) in maxwell. The 2D FEA shows that the eddy-current loss and the resistance torque increase as the rotor speed increases, and the eddy-current magnetic field will affect the air-gap magnetic field and reduce the electromagnetic force. The 3D FEA shows that dividing the rotor in insulate sheets can reduce the eddy-current loss. The loss and the sheets thickness have a linear relationship, which is different from the theoretical analysis.


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