• Title/Summary/Keyword: harmonic vector field

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Comparison and Analysis of Armature Reaction Magnetic Field of Linear Generator with Coreless/Cored Type Three Phases Concentrated Winding by using Space Harmonic Analytical Method (3상 집중권 권선을 갖는 코어리스/코어드 타입 리니어 발전기의 공간고조파 해석법을 이용한 전기자 반작용 자계특성 해석)

  • Seo, Sung-Won;Koo, Min-Mo;Kang, Han-Bit;Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.1
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    • pp.64-71
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    • 2015
  • This paper deals with analysis of armature reaction magnetic field of linear generator with three phases coreless/cored type concentrated winding. On the basis of a magnetic vector potential and Maxwell's equations, governing equations to predict armature reaction field are derived, and current density modeling is also performed analytically by using the Fourier series expansion. The analytical method used in this paper is confirmed by comparing with finite element analysis results.

A Vector Control System for Five-Phase Squirrel-Cage Induction Motor Considering Effects of 3rd Current Harmonics Component (제3 고조파 전류성분의 영향을 고려한 5상 농형 유도전동기의 벡터제어 시스템)

  • Kim, Min-Huei;Kim, Nam-Hun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.61 no.4
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    • pp.206-213
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    • 2012
  • This paper propose a improved speed control system for five-phase squirrel-cage induction motor(IM) considering effects of 3rd. harmonic current components with field oriented control(FOC) A five-phase IM drives present unique characteristics due to the additional degrees of freedom and also drives possess many others advantage compared with the traditional three-phase motor drive system, such as reducing a amplitude of torque pulsation at low frequency and increasing the reliability. In order to maximize the torque per ampere, the proposed motor has concentrated windings. The produced back-electromotive force is almost trapezoidal, and the motor is supplied with the combined sinusoidal plus third harmonic of currents. There is necessary to controlled 3rd harmonic current. For presenting the superior performance of the proposed the speed control system, experimental results are presented using a 32-bit fixed point TMS320F2812 DSP with 1.5[KW] induction motor.

Harmonic seismic waves response of 3D rigid surface foundation on layer soil

  • Messioud, Salah;Sbartai, Badredine;Dias, Daniel
    • Earthquakes and Structures
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    • v.16 no.1
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    • pp.109-118
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    • 2019
  • This study, analyses the seismic response for a rigid massless square foundation resting on a viscoelastic soil layer limited by rigid bedrock. The foundation is subjected either to externally applied forces or to obliquely incident seismic body or surface harmonic seismic waves P, SV and SH. A 3-D frequency domain BEM formulation in conjunction with the thin layer method (TLM) is adapted here for the solution of elastodynamic problems and used for obtained the seismic response. The mathematical approach is based on the method of integral equations in the frequency domain using the formalism of Green's functions (Kausel and Peck 1982) for layered soil, the impedance functions are calculated by the compatibility condition. In this study, The key step is the characterization of the soil-foundation interaction with the input motion matrix. For each frequency the impedance matrix connects the applied forces to the resulting displacement, and the input motion matrix connects the displacement vector of the foundation to amplitudes of the free field motion. This approach has been applied to analyze the effect of soil-structure interaction on the seismic response of the foundation resting on a viscoelastic soil layer limited by rigid bedrock.

Hybrid Pulse Width Modulation Strategy for Wide Speed Range in IPMSM with Low Cost Drives

  • Ahn, Han-woong;Go, Sung-chul;Lee, Ju
    • Journal of Electrical Engineering and Technology
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    • v.11 no.3
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    • pp.670-674
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    • 2016
  • The control performance of hybrid PWM inverter using a phase current measurement is presented in this paper. The hybrid PWM technique consists of space vector pulse width modulation (SVPWM) and six-step voltage control operation. The SVPWM is performed to reduce the harmonic components in the low speed region, and the six-step modulation is applied to increase the maximum speed of the IPMSM in the high speed region. Therefore, it is possible to obtain a great performance in both the low speed range and high speed range. However, the six-step modulation cannot be completely implemented, since the inverter that includes the lag-shunt sensing method has an immeasurable current region. In this paper, a quasi-six-step modulation using a modified voltage vector is proposed. The validity and usefulness of the proposed PWM technique is verified by MATLAB/Simulink and experimental results.

Quasi-3D analysis of Axial Flux Permanent Magnet Rotating Machines using Space Harmonic Methods (공간고조파법을 이용한 축 자속 영구자석 회전기기의 준(準)-3D 특성 해석)

  • Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.5
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    • pp.942-948
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    • 2011
  • This paper deals with characteristic analysis of axial flux permanent magnet (AFPM) machines with axially magnetized PM rotor using quasi-3-D analysis modeling. On the basis of magnetic vector potential and a two-dimensional (2-D) polar-coordinate system, the magnetic field solutions due to various PM rotors are obtained. In particular, 3-D problem, that is, the reduction of magnetic fields near outer and inner radius of the PM is solved by introducing a special function for radial position. And then, the analytical solutions for back-emf and torque are also derived from magnetic field solutions. The predictions are shown in good agreement with those obtained from 3-D finite element analyses (FEA). Finally, it can be judged that analytical solutions for electromagnetic quantities presented in this paper are very useful for the AFPM machines in terms of following items : initial design, sensitivity analysis with design parameters, and estimation of control parameters.

Eddy current loss calculation of flux shield in the large turbo generator using axi-periodic analysis (Axi-periodic Analysis를 이용한 대형 터보 발전기 단부 Flux Shield의 Eddy Current Loss 산정)

  • Kwon, Soon-O;Lee, Jung-Jong;Hong, Jung-Pyo;Nam, Hyuk
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.987-989
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    • 2005
  • Axi-periodic analysis using magnetic vector potential is formulated in time harmonic field and applied to the field analysis for the end region of large turbo generator in this paper. By using axi-periodic analysis, the effect of flux shield, one of the structure placed in the end region of large turbo generator to prevent stator end from thermal damage, is studied, and eddy current loss in the flux shield is estimated for operation conditions. 3D FEA is used for the verification of presented analysis method. Because 3D flux distribution can be calculated with 2D modeling, magnetic field showing 3D distribution can be effectively calculated by axi-periodic analysis comparing with 3D FEA.

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Improved Method for Calculating Magnetic Field of Surface-Mounted Permanent Magnet Machines Accounting for Slots and Eccentric Magnet Pole

  • Zhou, Yu;Li, Huaishu;Wang, Wei;Cao, Qing;Zhou, Shi
    • Journal of Electrical Engineering and Technology
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    • v.10 no.3
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    • pp.1025-1034
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    • 2015
  • This paper presented an improved analytical method for calculating the open-circuit magnetic field in the surface-mounted permanent magnet machines accounting for slots and eccentric magnet pole. Magnetic field produced by radial and parallel permanent magnet is equivalent to that produced by surface current according to equivalent surface-current method of permanent magnet. The model is divided into two types of subdomains. The field solution of each subdomain is obtained by applying the interface and boundary conditions. The magnet field produced by equivalent surface current is superposed according to superposition principle of vector potential. The investigation shows harmonic contents of radial flux density can be reduced a lot by changing eccentric distance of eccentric magnet poles compared with conventional surface-mounted permanent-magnet machines with concentric magnet poles. The FE(finite element) results confirm the validity of the analytical results with the proposed model.

General Analytical Method for Magnetic Field Analysis of Halbach Magnet Arrays Based on Magnetic Scalar Potential

  • Jin, Ping;Yuan, Yue;Lin, Heyun;Fang, Shuhua;Ho, S.L.
    • Journal of Magnetics
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    • v.18 no.2
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    • pp.95-104
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    • 2013
  • This paper presents a general analytical method for predicting the magnetic fields of different Halbach magnet arrays with or without back iron mounted on slotless permanent magnet (PM) linear machines. By using Fourier decomposition, the magnetization components of four typical Halbach magnet arrays are determined. By applying special synthetic boundary conditions on the PM surfaces, the expressions of their magnetic field distributions are derived based on the magnetic scalar potential (MSP), which are simpler than those based on the magnetic vector potential (MVP). The correctness of the method is validated by finite element analysis. The harmonics of airgap flux density waveforms of these Halbach magnet arrays with or without back iron are also compared and optimized.

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).

Characteristic analysis of Interior Permanent Magnet Synchronous Motors Considering Voltage Harmonics (전압 고조파를 고려한 매입형 영구자석 동기전동기의 d-q 등가회로 해석)

  • Kwon, Soon-O;Lee, Geun-Ho;Lee, Woo-Taik;Hong, Jung-Pyo
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.985-986
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    • 2011
  • This paper deals with d-q axis equivalent circuit analysis of IPMSM(Interior Permanent Magnet Synchronous Motors) considering voltage harmonics. In the field weakening region, as the current vector angle increased, back-emf contains large harmonics, therefore, significant underestimation of voltage or overestimation of speed can be occurred from the conventional d-q axis equivalent circuit analysis. In order to consider the effects of voltage harmonics, a harmonic coefficient is introduced and verified by experiments.

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