• Title, Summary, Keyword: Eddy current loss

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Eddy Current Loss Analysis in Radial Flux Type Synchronous Permanent Magnet Coupling using Space Harmonic Methods (공간고조파법을 이용한 반경방향 영구자석을 갖는 자기커플링의 와전류 손실 해석)

  • Min, Kyoung-Chul;Kang, Han-Bit;Park, Min-Gyu;Cho, Han-Wook;Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.10
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    • pp.1377-1383
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    • 2014
  • This paper deals with eddy current loss of magnetic coupling with radial permanent magnet (PM) using analytical method such as a space harmonic method. Superposition of two kinds analysis model is used to analyze eddy current loss induced in inner PM and outer PM of magnetic coupling. When the eddy current is induced, the environmental temperature increases, and the permanent magnet(PM) characteristics are degraded because the performance of PM is greatly influenced by temperature rise. Hence, the calculation of eddy current loss becomes an important factor in the magnetic coupling. In order to analyze eddy current loss, first, on the basis of the magnetic vector potential and two-dimensional(2-D) polar-coordinate system, the magnetic field solutions of the radial magnetized PM are obtained. And we obtain the analytical solutions for the eddy current density produced by permanent magnet. Lastly, analytical solutions for eddy current loss are derived by using equivalent, electrical resistance calculated from magnet volume and analytical solution for eddy current density. This analytical results are validated by comparing with the 2-D finite element analysis (FEA).

Numerical Investigation on Permanent-Magnet Eddy Current Loss and Harmonic Iron Loss for PM Skewed IPMSM

  • Lim, Jin-Woo;Kim, Yong-Jae;Jung, Sang-Yong
    • Journal of Magnetics
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    • v.16 no.4
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    • pp.417-422
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    • 2011
  • This paper presents the characteristics of PM eddy current loss and harmonic iron loss for PM step-skewed Interior Permanent Magnet Synchronous Motor (IPMSM) with concentrated windings and multi-layered PM under the running condition of maximum torque per ampere (MTPA) and flux-weakening control. In particular, PM eddy current loss and harmonic iron loss in IPMSM have been numerically computed with three-dimensional Finite Element Analysis (3D FEA), whereby IPMSM with concentrated windings and multi-layered PM has been designed to identify the optimized skew angle contributing to the reduced PM eddy current loss and torque ripples, while maintaining the required average torque. Furthermore, numerical investigation on PM eddy current loss and iron loss at MTPA and flux-weakening control has been carried-out in terms of PM step-skew.

Novel Claw Pole Eddy Current Load for Testing DC Counter Rotating Motor - Part II: Design and Modeling

  • Kanzi, Khalil;Roozbehani, Sam;Dehafarin, Abolfazl;Kanzi, Majid
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.4
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    • pp.412-418
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    • 2012
  • Eddy current brakes are electromechanical devices used as variable mechanical loads for testing electrical machines. Accurate modeling of eddy current loss is an important t factor for optimum design of eddy brake systems. In this second part, we propose novel formulations of eddy current loss in novel claw-pole eddy brake system. The proposed model for eddy current loss in novel claw-pole eddy brake system depends on the size of the claw poles. Also, in this paper, the flux density is measured by using the magnetic circuit of the novel claw pole. The model results are compared with experimental results and they are found to be in good agreement.

Improved Design to reduce Eddy Current Loss in Retain Ring in Superconducting Machines

  • Lee, Sang-Ho;Jung, Jae-Woo;Sun, Tao;Hong, Jung-Pyo;Kim, Yeong-Chun
    • Progress in Superconductivity and Cryogenics
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    • v.13 no.2
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    • pp.13-16
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    • 2011
  • This paper describes the reduction method of eddy current loss generated into a retaining ring installed in wound-field superconducting machine. In order to suggest the reduction method of eddy current loss of the retaining ring, this paper is divided into three parts. Firstly, eddy current loss of prototype model is calculated. Secondly, eddy current loss versus material and shape of the retaining ring is compared. Finally, the material and the shape of the retaining ring to reduce coupling loss generated by a time-varying magnetic field are proposed. In this paper, eddy current loss is calculated by 3-dimensional transient analysis.

Analysis of Permanent Magnet Eddy Current Loss by Permanent Magnet Attaching Method of Magnetic Gears (마그네틱 기어의 영구자석 부착방법에 따른 영구자석 와전류손실 분석)

  • Park, Eui-Jong;Kim, Sung-Jin;Jung, Sang-Yong;Kim, Yong-Jae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.6
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    • pp.911-915
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    • 2017
  • Recently, there has been an increasing interest in the non-contact power transmission method of magnetic gears. Since there is no mechanical contact, noise caused by friction can be reduced, and even if a sudden large force is applied, the impact of the gear is close to zero. Further, since the power is transmitted by the magnetic flux, it has high reliability. However, there is a problem that a loss due to a magnetic field due to use of a magnetic flux. The loss caused by the magnetic field of the magnetic gear is a joule loss called eddy current loss. In addition, the eddy current loss in the magnetic gear largely occurs in the permanent magnet, but it is a fatal loss to the permanent magnet which is vulnerable to heat. Particularly, magnetic gears requiring high torque density use NdFeB series permanent magnets, and this permanent magnets have a characteristic in which the magnetic force decreases as temperature increases. Therefore, in this paper, the eddy current loss of the permanent magnet according to the permanent magnet attaching method is analyzed in order to reduce the eddy current loss of the permanent magnet. We have proposed a structure that can reduce the eddy current loss through the analysis and show the effect of reducing the loss of the proposed structure.

Eddy-Current Loss Analysis in Rotor of Surface-Mounted Permanent Magnet Machines Using Analytical Method (해석적 방법을 이용한 표면부착형 영구자석 기기의 회전자 와전류 손실해석)

  • Choi, Jang-Young;Choi, Ji-Hwan;Jang, Seok-Myeong;Cho, Han-Wook;Lee, Sung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.8
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    • pp.1115-1122
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    • 2012
  • This paper analyzes eddy-current loss induced in magnets of surface-mounted permanent magnet (SPM) machines by using an analytical method such as a space harmonic method. First, on the basis of a two-dimensional (2D) polar coordinate system and a magnetic vector potential, the analytical solutions for the flux density produced by armature winding current are obtained. By using derived field solutions, the analytical solutions for eddy current density distribution are also obtained. Finally, analytical solutions for eddy current loss induced in rotor magnets are derived by using equivalent electrical resistance calculated from magnet volume and analytical solutions for eddy-current density distribution. In particular, the influence of time harmonics in armature current on the eddy current loss is fully investigated and discussed. All analytical results are validated extensively by finite element analysis (FEA).

Study on the Power Loss of High Frequency Mn-Zn ferrites (고주파 Mn-Zn ferrites 전력손실에 대한 고찰)

  • 서정주
    • Journal of the Korean Institute of Resources Recycling
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    • v.11 no.5
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    • pp.34-38
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    • 2002
  • To minimize the size of transformer volume, the operating frequency of ferrites cores increasing. The power loss of Mn-Zn ferrites comprises hysteresis loss, eddy current loss and residual loss. In the range more then 500 KHz, the total power loss is mainly due to the residual loss. The power loss increase with the frequency 3rd power. To minimize residual loss as well as eddy current loss, the microstructure should have small grain and high density, It should be noted that as the product of resonance frequency and static permeability increase, the power loss decrease at high frequency region.

Analysis of Eddy Current Loss in Brushless DC Motor according to the Swiching Frequency of the PWM Inverter (PWM 인버터의 스위칭 주파수에 따른 브러시레스 DC 모터에서의 와전류 손실 특성 해석)

  • Kim, Wa-Sung;Choi, Tae-Sik;Kim, Youn-Hyun;Lee, Ju
    • Proceedings of the KIEE Conference
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    • pp.675-677
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    • 2000
  • In the paper the eddy current loss in brushless DC motor due to switching frequency supplied by PWM inverter, is analyzed. The compensated conductivity is used in order to analyze the eddy current loss in brushless DC motor which has lamination structure. The eddy current loss is deceased when switching frequency supplied by PWM inverter is gradually increased from 1.2kHz up to 12kHz. The high switching frequency of PWM inverter make the output wave into a similar sine wave and this leads to the decreasing eddy current loss.

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Eddy Current Loss Analysis of Slotless Double-sided Cored Type Permanent Magnet Generator by using Analytical Method (해석적 방법을 이용한 슬롯리스 양측식 코어드 타입 영구자석 발전기의 와전류 손실 해석)

  • Jang, Gang-Hyeon;Jung, Kyoung-Hun;Hong, Keyyong;Kim, Kyong-Hwan;Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.10
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    • pp.1639-1647
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    • 2016
  • This paper deals with eddy current loss analysis of Slotless Double sided Cored type permanent magnet linear generator by using analytical method, space harmonic method. In order to calculate eddy current, this paper derives analytical solution by the Maxwell equation, magnetic vector potential, Faraday's law and a two-dimensional(2-D) cartesian coordinate system. First, we derived the armature reaction field distribution produced by armature wingding current. Second, by using derived armature reaction field solution, the analytical solution for eddy current density distribution are also obtained. Finally, the analytical solution for eddy current loss induced in permanent magnets(PMs) are derived by using equivalent, electrical resistance calculated from PMs volume and eddy current density distribution solution. The analytical result from space harmonic method are validated extensively by comparing with finite element method(FEM).

2-D Finite Element Analysis of Brushless DC Motor Considering Eddy Current (와전류 손실을 고려한 브러시리스 DC 모터의 2차원 유한 요소 해석)

  • Choi, Tae-Sik;Chun, Yon-Do;Lee, Ju;Lim, Tae-Bin;Kim, Suk-Tae
    • Proceedings of the KIEE Conference
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    • pp.49-51
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    • 1999
  • This paper presents an efficient 2D finite element analysis(FEA) for brushless DC motor (BLDCM) taking into account the eddy current and lamination effect of stator. In BLDCM, the dynamic characteristic analysis considering the eddy current and driving circuit is applied for the accurate prediction of motor performance in high speed because the eddy current loss is proportional of square of the driving frequency. According to the variation of lamination number, the characteristics of electro magnetic force, torque, and eddy current loss are analyzed. From the results, it is known that the effect of the lamination of stator on the eddy current loss is verified.

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