Extended Summary 本文は pp.516–522 Mode-Filtering Analysis Method of Space and Time Harmonic Wave Components of Magnetic Fields in Rotating Machinery Kenji Miyata Member (Hitachi, Ltd.) Kazumasa Ide Senior Member (Hitachi, Ltd.) Kazuo Shima Member (Kanazawa Institute of Technology) Keywords: rotating machinery, magnetic field analysis, finite element method, space harmonic wave, time harmonic wave We propose a new analysis method of harmonic wave compo- nents of magnetic fields in rotating machinery. First, the transient analysis of nonlinear magnetic field is excuted taking into account an eddy current field by using the finite element method. The field on the sliding surface is expanded into a number of harmonic wave components. Figures 1 and 2 indicate the transient behaviors of the amplitudes and phases of the harmonic waves on the sliding surface. The amplitude of the 1 st mode is very large (11.43 ± 0.09 mWb) and so is not shown in Fig. 1. The 1 st mode is a fundamental one of the rotating machinery which is followed by the harmonic waves of odd number mode, while the harmonic waves of even number mode are not synchronized with the fundamental mode. In the next process, the magnetic permeability obtained by the transient analysis is embedded on all the magnetic finite elements in the FEM analysis, and the harmonic wave components are set on the sliding surface as the boundary condition. All magnetomo- tive force of permanent magnets and coil currents is switched off, and individual fields on the harmonic wave boundary condition are analysed taking into account eddy current fields for the rotor and stator spaces. For the robust analysis, the eddy current term should be added to the right hand side source term with iterative calcu- lations. Figure 3 shows the magnetic flux lines and magnet eddy current density of the 2nd mode at 691st step. On the other hand, all magnetomotive force is switched on, and the source mode field is analysed under the boundary condition of zero field on the slid- ing surface. The sum magnetic field of the harmonic modes and the source mode agree well with the original transient field. The fields of source mode and the harmonic modes are visualized in animation style showing the transient behaviors. The field analysis requires only linear magnetic field analysis, and therefore the cpu time of the harmonic mode analysis is only 10–20 times longer than that of the original transient wave analy- sis despite computing a large number of calculations for rotor and stator spaces. Figure 4 shows the time-averaged eddy current loss for the con- ventional transient analysis (A), the loss obtained by the sum field of the source mode and 0-30 harmonic wave modes (B), the sum of the losses of the source mode and 0-30 harmonic wave modes (C), and the loss of the source mode and the harmonic wave mode(S, 0, 1, 2, 3,. . . , 10). The value of (B) has approximately the same value as (A). However, the value of (C) is 1.6 times larger than the value of (A) because all the negative effects of the coupling terms between the harmonic waves are neglected. But, the eddy current losses of the harmonic waves can be used as indicators to compare the relative effects to eddy current field. The mode separation of magnetic field will contribute to the study of reducing the harmful harmonic wave components for the rotating machinery. Fig. 1. Transient behavior of space harmonic wave am- plitudes Fig. 2. Transient behavior of phases of space harmonic waves Fig. 3. Magnetic flux lines and eddy current density of 2nd mode at 691st step (Jmin = -1.52 × 10 5 A/m 2 , Jmax = 1.59 × 10 5 A /m 2 ) Fig. 4. Time-averaged eddy current loss (A: Conven- tional transient analysis, B: Loss obtained by the sum field of s and 0-30modes, C: Sum of s and 0-30modes’ losses, S: Source mode) –20–
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Extended Summary 本文は pp.516–522
Mode-Filtering Analysis Method of Space and Time Harmonic WaveComponents of Magnetic Fields in Rotating Machinery
Kenji Miyata Member (Hitachi, Ltd.)
Kazumasa Ide Senior Member (Hitachi, Ltd.)
Kazuo Shima Member (Kanazawa Institute of Technology)
Keywords: rotating machinery, magnetic field analysis, finite element method, space harmonic wave, time harmonic wave
We propose a new analysis method of harmonic wave compo-nents of magnetic fields in rotating machinery. First, the transientanalysis of nonlinear magnetic field is excuted taking into accountan eddy current field by using the finite element method. The fieldon the sliding surface is expanded into a number of harmonic wavecomponents. Figures 1 and 2 indicate the transient behaviors of theamplitudes and phases of the harmonic waves on the sliding surface.The amplitude of the 1st mode is very large (11.43±0.09 mWb) andso is not shown in Fig. 1. The 1st mode is a fundamental one of therotating machinery which is followed by the harmonic waves of oddnumber mode, while the harmonic waves of even number mode arenot synchronized with the fundamental mode.
In the next process, the magnetic permeability obtained by thetransient analysis is embedded on all the magnetic finite elementsin the FEM analysis, and the harmonic wave components are seton the sliding surface as the boundary condition. All magnetomo-tive force of permanent magnets and coil currents is switched off,and individual fields on the harmonic wave boundary condition areanalysed taking into account eddy current fields for the rotor andstator spaces. For the robust analysis, the eddy current term shouldbe added to the right hand side source term with iterative calcu-lations. Figure 3 shows the magnetic flux lines and magnet eddycurrent density of the 2nd mode at 691st step. On the other hand,all magnetomotive force is switched on, and the source mode fieldis analysed under the boundary condition of zero field on the slid-ing surface. The sum magnetic field of the harmonic modes and thesource mode agree well with the original transient field. The fieldsof source mode and the harmonic modes are visualized in animationstyle showing the transient behaviors.
The field analysis requires only linear magnetic field analysis,and therefore the cpu time of the harmonic mode analysis is only10–20 times longer than that of the original transient wave analy-sis despite computing a large number of calculations for rotor andstator spaces.
Figure 4 shows the time-averaged eddy current loss for the con-ventional transient analysis (A), the loss obtained by the sum fieldof the source mode and 0-30 harmonic wave modes (B), the sum ofthe losses of the source mode and 0-30 harmonic wave modes (C),and the loss of the source mode and the harmonic wave mode(S,0, 1, 2, 3,. . . , 10). The value of (B) has approximately the samevalue as (A). However, the value of (C) is 1.6 times larger than thevalue of (A) because all the negative effects of the coupling termsbetween the harmonic waves are neglected. But, the eddy currentlosses of the harmonic waves can be used as indicators to comparethe relative effects to eddy current field.
The mode separation of magnetic field will contribute to the studyof reducing the harmful harmonic wave components for the rotatingmachinery.
Fig. 1. Transient behavior of space harmonic wave am-plitudes
Fig. 2. Transient behavior of phases of space harmonicwaves
Fig. 3. Magnetic flux lines and eddy current density of2nd mode at 691st step (Jmin = −1.52 × 105 A/m2,Jmax = 1.59 × 105A /m2)
Fig. 4. Time-averaged eddy current loss (A: Conven-tional transient analysis, B: Loss obtained by the sumfield of s and 0-30modes, C: Sum of s and 0-30modes’losses, S: Source mode)
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論 文
回転機における時間・空間高調波磁場成分に関する分析法
正 員 宮田 健治∗ 上級会員 井出 一正∗
正 員 島 和男∗∗
Mode-Filtering Analysis Method of Space and Time Harmonic Wave Components ofMagnetic Fields in Rotating Machinery
Kenji Miyata∗, Member, Kazumasa Ide∗, Senior Member, Kazuo Shima∗∗, Member
We propose a new analysis method of harmonic wave components of magnetic fields in rotating machinery. Using
the magnetic permeability obtained by the transient analysis of nonlinear magnetic field, the harmonic wave com-
ponents of the magnetic field are individually calculated both in the spaces of rotor and stator under the boundary
condition that the harmonic wave components obtained by the transient analysis are set on the sliding surface. The
mode separation of magnetic field will contribute to the study of reducing the harmful harmonic wave components for
the rotating machinery.
キーワード:回転機,磁場解析,有限要素法,空間高調波,時間高調波
Keywords: rotating machinery, magnetic field analysis, finite element method, space harmonic wave, time harmonic wave
図 4 0次の空間高調波の時間変化Fig. 4. Transient behavior of 0th mode amplitude.
図 5 各空間高調波振幅 an の時間変化Fig. 5. Transient behavior of space harmonic waveamplitudes.
図 6 各空間高調波位相 ϕn の時間変化Fig. 6. Transient behavior of phases of space harmonicwaves.
図 7 磁束線と渦電流密度分布(691ステップ目)Fig. 7. Magnetic flux lines and eddy current density at691st step (Jmin = −2.74 × 105 A/m2, Jmax = 2.18 ×105 A/m2).
電学論 D,128 巻 4 号,2008 年 519
図 8 Sモードの磁束線と渦電流密度分布(691ステップ目)
Fig. 8. Magnetic flux lines and eddy current density ofS-mode at 691st step (Jmin = −1.35 × 105 A/m2, Jmax =1.04 × 105 A/m2).
図 9 0次モードの磁束線と渦電流密度分布(691ステップ目)
Fig. 9. Magnetic flux lines and eddy current densityof 0th mode at 691st step (Jmin = −6.44 × 102 A/m2,Jmax = 1.25 × 103 A/m2).
図 10 1次モードの磁束線と渦電流密度分布(691ステップ目)
Fig. 10. Magnetic flux lines and eddy current densityof 1st mode at 691st step (Jmin = −5.00 × 104 A/m2,Jmax = 4.39 × 104 A/m2).
図 11 2次モードの磁束線と渦電流密度分布(691ステップ目)
Fig. 11. Magnetic flux lines and eddy current densityof 2nd mode at 691st step (Jmin = −1.52 × 105 A/m2,Jmax = 1.59 × 105 A/m2).
図 12 3次モードの磁束線と渦電流密度分布(691ステップ目)
Fig. 12. Magnetic flux lines and eddy current densityof 3rd mode at 691st step (Jmin = −8.55 × 104 A/m2,Jmax = 8.53 × 104 A/m2).
図 13 4次モードの磁束線と渦電流密度分布(691ステップ目)
Fig. 13. Magnetic flux lines and eddy current densityof 4th mode at 691st step (Jmin = −1.48 × 105 A/m2,Jmax = 1.48 × 105 A/m2).
図 14 5次モードの磁束線と渦電流密度分布(691ステップ目)
Fig. 14. Magnetic flux lines and eddy current densityof 5th mode at 691st step (Jmin = −4.37 × 103 A/m2,Jmax = 4.34 × 103 A/m2).
図 15 30次までのすべてのモードを合成した場の磁束線と渦電流密度分布(691ステップ目)
Fig. 15. Magnetic flux lines and eddy current densityobtained by the sum of S-mode and 0-30th modes at 691ststep (Jmin = −2.45×105 A/m2, Jmax = 2.63×105 A/m2).
図 16 時間平均渦電流損Fig. 16. Time-averaged eddy current loss (A: Conven-tional transient analysis, B: Loss obtained by the sumfield of s and 0-30modes, C: Sum of s and 0-30modes’losses, S: S-mode).
( 3) H. Mikami, K. Ide, K. Arai, M. Takahashi, and K. Kajiwara: “Analysis ofhigher harmonic components in magnetic fields on three phase squirrel-cageinduction motors considering higher harmonics in the secondary current”,Trans. IEE of Japan, Vol.116-D, No.2, pp.158–166 (1996) (in Japanese)三上浩幸・井出一正・新井啓治・高橋身佳・梶原憲三:「高調波二次電流を考慮した三相かご形誘導電動機の機内高調波磁場解析」,電学論 D, 116, 2, pp.158–166 (1996)
( 4) K. Yamazaki and S. Watari: “A study on loss analysis of synchronous per-manent magnet motors using combination of 2-D and 3-D finite elementmethod”, The Papers of Joint Technical Meeting on Static Apparatus andRotating Machinery, IEE Japan, SA-03-74/RM-03-76 (2003) (in Japanese)山崎克己・渡伸次郎:「三次元・二次元併用有限要素法による永久磁石同期電動機の損失解析に関する検討」,電学静止器・回転機合同研資, SA-03-74/RM-03-76 (2003)
( 5) K. Yamazaki and H. Satou: “Loss analysis of synchronous permanent mag-net motors using combination of 2-D and 3-D finite element method—Comparison between proposed method and full 3D analysis—”, The Papersof Joint Technical Meeting on Static Apparatus and Rotating Machinery,IEE Japan, SA-04-59/RM-04-83 (2004) (in Japanese)山崎克己・佐藤寛之:「三次元・二次元併用有限要素法による永久磁石同期電動機の損失解析—フル三次元解析との比較—」,電学静止器・回転機合同研資, SA-04-59/RM-04-83 (2004)
( 9) K. Miyata, K. Ide, and K. Shima: “Proposed analysis method of space andtime harmonic wave components of magnetic fields in rotating machinery”,The Papers of Technical Meeting on Rotating Machinery, IEE Japan, RM-05-111 (2005) (in Japanese)宮田健治・井出一正・島 和男:「回転機における時間・空間高調波磁場分布の分析方法の提案」,電学回転機研資, RM-05-111 (2005)
(10) J.C. Nedelec: “Mixed Finite Elements in R3”, Numer. Math., Vol.35,pp.315–341 (1980)
(11) A. Bossavit: “Whitney forms: a class of finite elements for three-dimensional computations in electromagnetism”, IEE Proc., Vol.135, No.8,pp.493–500 (1988)