• Title/Summary/Keyword: Multi-pole Magnet

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Characteristic of Moving Coil type Linear Oscillatory Actuator by Multi-Pole Permancent Magnet Arrangement (영구자석 다극 배치에 의한 가동 코일형 리니어 진도 엑츄에이터의 특성)

  • 김덕현;강규홍;홍정표;김규탁
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.50 no.6
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    • pp.273-281
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    • 2001
  • In order to overcome the demerit and to improve the operation characteristics of Moving Coil type Linear Oscillatory Actuator(MC-LOA) with single-pole permanent magnet, this paper presents two models having the balanced magnetic circuit by multi-pole permanent magnet. They are short coil type with two-pole single-sided and two-ple double-sided permanent magnet. The characteristics between single-pole and multi-pole permanent magnet type MC-LOA are compared. As a result, multi-pole type MC-LOA has more merits than single-pole type about operation characteristics improvement and machine volume. The characteristics analysis is performed by their dynamic analysis composed of kinetic and electric equations and Finite Element Method(FEM). The propriety of multi-pole type MC-LOA model is verified with analysis results.

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Design and Analysis of a Vibration-Driven Electromagnetic Energy Harvester Using Multi-Pole Magnet

  • Munaz, Ahmed;Chung, Gwiy-Sang
    • Journal of Sensor Science and Technology
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    • v.21 no.3
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    • pp.172-179
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    • 2012
  • This paper presents the design and analysis of a vibration-driven electromagnetic energy harvester that uses a multi-pole magnet. The physical backgrounds of the vibration electromagnetic energy harvester are reported, and an ANSYS finite element analysis simulation has been used to determine the different alignments of the magnetic pole array with their flux lines and density. The basic working principles for a single and multi-pole magnet are illustrated and the proposed harvester has been presented in a schematic diagram. Mechanical parameters such as input frequency, maximum displacement, number of coil turns, and load resistance have been analyzed to obtain an optimized output power for the harvester through theoretical study. The paper reports a maximum of 1.005 mW of power with a load resistance of $1.9k{\Omega}$ for 5 magnets with 450 coil turns.

Effects of Magnetizing Currents on Remanent Flux Density in Multipole Magnetizer (다극착자기에서 착자전류가 잔류자속밀도에 미치는 영향)

  • 박관수;이향범;배동진;한송엽;최홍순;홍정표;주관정
    • Journal of the Korean Magnetics Society
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    • v.2 no.2
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    • pp.145-149
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    • 1992
  • The characteristics of electromagnetic devices with permanent magnet depends greatly on the remanence pattern of permanent magnet. So, it is necessary to analyze the pattern of remanence in permanent magnet. This paper presents a finite element analysis of magnetizer considering the nonlinearity and anisotropy of yoke and magnet in magnetizer. The distributions of magnetizations are obtained according to the variations of magnetizing currents for two kinds of magnetizers with different magnetizing poles. It is found that the excessive magnetizing current results in the reduction and polarity reversion of magnetization in the multi-pole magnetizing system where the pole angle is too small. During the design and analyzing of multi-pole magnetizer, it must be considered that there exists an optimal value of magnetizing current and pole angle of magnetizer.

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Study of the Reduction of Torque Ripples for Multi-pole Interior Permanent Magnet Synchronous Motors using Rotor Saliency (회전자 돌극 설계를 이용한 다극 매입형 영구자석 동기전동기의 토크리플 저감 연구)

  • Kim, Ki-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.10
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    • pp.6270-6275
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    • 2014
  • The paper reports an improvement method on torque ripples of multi-pole interior permanent magnet synchronous motor (IPMSM) applied to a traction motor for hybrid electric vehicles. In the case of multi-pole IPMSM, the magnetic flux generated by a permanent magnet tends to leak through the bridge of the rotor without a link with stator windings. The slit design on the rotor surface was proposed to reduce torque rippling and increase the output power by reducing the leakage flux. Two design parameters for the slit are suggested for optimal design using the response surface method. As an analysis method, the 2D finite element method (FEM) was applied to consider magnetic saturation effect.

A Study on Reducing Rolling Mode Effect in High-Sensitivity Optical Pickup 3-axis Actuator (고감도 3축구동 액츄에이터를 위한 Rolling Mode 저감 연구)

  • 김영중;홍삼열;김진아;최인호
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.775-779
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    • 2003
  • Recently, a new type actuator using multi-pole magnet has been developed for high-density and high-speed disk drive, which can be achieved higher sensitivity than a conventional actuator for applying one-pole magnet. However, it is very difficult for the actuator of multi-pole magnet to meet simultaneously the optimal design condition for reducing rolling mode effect and improving driving sensitivity because the force center is different from the mass center In this paper, First We propose the new shape coil for tracking which can reverse moment additionally in tracking motion, Next we achieve the optimal design to reduce phase disturbance and peak gain at the rolling mode frequency. Finally, the validity of the proposed methods is proved from experimental results.

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Reduction and Analysis for Cogging Torque of Permanent Magnet Synchronous Generators with Multi-Pole Rotor for Wind Power Application (풍력발전용 영구자석 다극 동기발전기의 코깅토크의 해석 및 저감)

  • Jang, Seok-Myeong;Lee, Sung-Ho;Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.3
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    • pp.375-383
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    • 2008
  • This paper deals with reduction and analysis of cogging torque for permanent magnet synchronous generators with multi-pole rotor for wind power applications. Open-circuit field solutions are derived using a magnetic vector potential and a two-dimensional (2-d) polar coordinate systems. On the basis of derived open-circuit field solutions and 2-d permeance functions, we also derive open-circuit field solutions considering stator slotting effects. By using open-circuit field solutions considering stator slotting effects and energy variation methods, this paper analytically predicts the cogging torque considering skew effects. All analytical results are shown in good agreement with those obtained from finite element (FE) analyses. In order to reduce the cogging torque, by predicting the variation of the cogging torque according to pole arc/pitch ratio using analytical and FE methods, pole arc/pitch ratio which makes the cogging torque minimum are determined. However, we confirm that measured value for cogging torque of the PMG with determined pole arc/pitch ratio is twice higher than predicted value. Therefore, the reason for an error between measured and predicted cogging torque is discussed in terms of a shape of PMs and is proved experimentally.

Analytical Approach and Experimental Verification for the Cogging Torque Reduction of Permanent Magnet Machines with Multi-pole Rotor (다극 회전자를 갖는 영구자석 기기의 코깅토크 저감을 위한 해석적 접근 및 실험적 검증)

  • Jang, Seok-Myeong;Choi, Jang-Young;Ko, Kyoung-Jin
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1031-1032
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    • 2007
  • In order to reduce the cogging torque, by predicting the variation of the cogging torque according to pole arc/pitch ratio by analytical and FE methods, pole arc/pitch ratio which makes the cogging torque minimum are determined. And then, the measurements of cogging torque for permanent magnet generators with determined pole arc/pitch ratio are presented. The reasons for the error between predicted and measured value are discussed fully in terms of the shape of permanent magnet. Finally, by confirming that predicted results for cogging torque according to pole arc/pitch ratio and skew are shown in good agreement with those obtained from measured one, the validation of analysis results is confirmed.

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Design of Permanent Magnet Type Wind Power Generators for Cogging Torque Reduction with Optimum Pole Arc Pitch Ratio (코깅토크 저감을 위한 최적 극호비를 갖는 영구자석형 풍력발전기의 설계)

  • Jang, Seok-Myeong;Kim, Jin-Soon;Ko, Kyoung-Jin;Choi, Jang-Young;Yoon, Gi-Gab
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.38-40
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    • 2009
  • In order to achieve a gearless construction of the wind energy conversion system(WECS), a low-speed generator should be used. Of the various candidate machine types, radial-field, multi-pole, permanent magnet, synchronous machines may be used for low-speed applications. So, this paper deals with the design of direct-coupled, multi-pole radial field machines with permanent magnet(PM) excitation for wind power applications for cogging torque reduction through the determination of optimum pole arc/pitch ratio. On the basis of an equivalent magnetic circuit method(EMCM) and a space harmonic method(SHM), an initial design is performed considering restricted conditions. And then, a detailed design is made using a non-linear finite element analyses(FEA). Finally, test results concerning generating characteristics are given to confirm the validation of the design.

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A Study on the Optimization Strategy using Permanent Magnet Pole Shape Optimization of a Large Scale BLDC Motor (대용량 BLDC 전동기의 영구자석 형상 최적화를 통한 최적화 기법 연구)

  • Woo, Sung-Hyun;Shin, Pan-Seok;Oh, Jin-Seok;Kong, Yeong-Kyung;Bin, Jae-Goo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.5
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    • pp.897-903
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    • 2010
  • This paper presents a response surface method(RSM) with Latin Hypercube Sampling strategy, which is employed to optimize a magnet pole shape of large scale BLDC motor to minimize the cogging torque. The proposed LHS algorithm consists of the multi-objective Pareto optimization and (1+1) evolution strategy. The algorithm is compared with the uniform sampling point method in view points of computing time and convergence. In order to verify the developed algorithm, a 6 MW BLDC motor is simulated with 4 design parameters (arc length and 3 variables for magnet) and 4 constraints for minimizing of the cogging torque. The optimization procedure has two stages; the fist is to optimize the arc length of the PM and the second is to optimize the magnet pole shape by using the proposed hybrid algorithm. At the 3rd iteration, an optimal point is obtained, and the cogging torque of the optimized shape is converged to about 14% of the initial one. It means that 3 iterations aregood enough to obtain the optimal design parameters in the program.

Optimal Rotor Shape Design of Asymmetrical Multi-Layer IPM Motors to Improve Torque Performance Considering Irreversible Demagnetization

  • Mirazimi, M.S.;Kiyoumarsi, A.;Madani, Sayed M.
    • Journal of Electrical Engineering and Technology
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    • v.12 no.5
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    • pp.1980-1990
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    • 2017
  • A study on the multi-objective optimization of Interior Permanent-Magnet Synchronous Motors (IPMSMs) with 2, 3, 4 and 5 flux barriers per magnetic pole, based on Genetic Algorithm (GA) is presented by considering the aspect of irreversible demagnetization. Applying the 2004 Toyota Prius single-layer IPMSM as the reference machine, the asymmetrical two-, three-, four- and five-layer rotor models with the same amount of Permanent-Magnets (PMs) is presented to improve the torque characteristics, i.e., reducing the torque pulsation and increasing the average torque. A reduction of the torque pulsations is achieved by adopting different and asymmetrical flux barrier geometries in each magnetic pole of the rotor topology. The demagnetization performance in the PMs is considered as well as the motor performance; and analyzed by using finite element method (FEM) for verification of the optimal solutions.