• 제목/요약/키워드: Rotor Core

검색결과 187건 처리시간 0.028초

유한요소 LES법에 의한 축류 회전차 팁 틈새의 유동해석 (Flow Analysis in the Tip Clearance of Axial Flow Rotor Using Finite-Element Large-Eddy Simulation Method)

  • 이명호
    • Journal of Advanced Marine Engineering and Technology
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    • 제33권5호
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    • pp.686-695
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    • 2009
  • Flow characteristics in linear axial cascade have been studied using large eddy simulation(LES) based on finite element method(FEM) to investigate details of the leakage flow in the tip clearance of axial flow rotor. STAR-CD(FVM) and PAT-Flow(FEM) have been adopted to solve the Navier-Stokes equations for the simulation of the unsteady turbulent flow. Numerical results from the present study have been compared with the existing experimental results to investigate a tip clearance effect on velocity profile and static pressure distribution on blade surface at various spanwise positions. Both simulation results agree well with the experimental data. However, it has been shown that the results of finite-element large-eddy simulation agree better with experimental data than $k-{\varepsilon}$ turbulent model based on finite volume method regarding the tip vortex geometry and static pressure distribution at the center of the tip vortex core. As a result of this study, it is shown that finite-element large-eddy simulation method can predict more exactly on the tip leakage vortex flow and behind flow field.

Design and control of a permanent magnet spherical wheel motor

  • Park, Junbo;Kim, Minki;Jang, Hyun Gyu;Jung, Dong Yun;Park, Jong Moon
    • ETRI Journal
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    • 제41권6호
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    • pp.838-849
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    • 2019
  • We present a permanent magnet-based spherical wheel motor that can be used in omnidirectional mobility applications. The proposed motor consists of a ball-shaped rotor with a magnetic dipole and a hemispherical shell with circumferential air-core coils attached to the outer surface acting as a stator. Based on the rotational symmetry of the rotor poles and stator coils, we are able to model the rotor poles and stator coils as dipoles. A simple physical model constructed based on a torque model enables fast numerical simulations of motor dynamics. Based on these numerical simulations, we test various control schemes that enable constant-speed rotation along arbitrary axes with small rotational attitude error. Torque analysis reveals that the back electromotive force induced in the coils can be used to construct a control scheme that achieves the desired results. Numerical simulations of trajectories confirm that even without explicit methods for correcting the rotational attitude error, it is possible to drive the motor with a low attitude error (<5°) using the proposed control scheme.

5상 1.5kW 농형 유도전동기의 운전특성 (Operating Characteristics of Squirrel-Cage Induction Motor of 5-Phase 1.5kW)

  • 김민회;정형우;송현직
    • 조명전기설비학회논문지
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    • 제28권5호
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    • pp.52-59
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    • 2014
  • This paper presents an improved operating characteristics of squirrel-cage induction motor(IM) for 5-phase 1.5kW, 220V, 60Hz in order to study a polyphase AC machinery that keep hold of advantages more than traditional three-phase a IM, such as reducing a amplitude of torque pulsation, decreasing electric noises, and increasing the reliability. The developed manufacturing motor was necessary to do improvement of speed regulation, efficiency, operating characteristics, and so on at rated load. There are remake a redesigned and distributed stator winding connection without changing the frames of stator and rotor core in previous established the motor by a repeat tests. There are shown a experiments results of no-load test, locked rotor test, operating characteristics at variable load, FFT analysis of harmonics within output voltages and current waveform, decided motor parameters.

기존 12/8 및 새로운 6/5 SRM의 성능분석 및 비교 (Performance Evaluation and Comparison of Conventional 12/8 and Novel 6/5 Switched Reluctance Motors)

  • 서진요;이동희;안진우
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2016년도 전력전자학술대회 논문집
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    • pp.517-518
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    • 2016
  • In this paper, a novel 6/5 switched reluctance motor (SRM) with segmental rotor is proposed for vehicle cooling fan application. Unlike conventional SRMs, the proposed motor adopts hybrid stator poles and segmental rotor structures, thereby making the motor operate in short flux paths and parts of the flux paths magnetically isolated between the phases. Therefore, compared with conventional SRMs, the proposed structure could improve the output torque density and reduce the core loss, thereby improving the electric utilization of the motor. To verify the proposed structure, the performance of the proposed structure is evaluated. Meanwhile, a conventional 12/8 SRM which has been used for vehicle cooling fan application is also evaluated. Finally, the effectiveness of the proposed SRM is demonstrated by the simulation and experimental results.

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분수슬롯 권선 타입의 매입형 영구자석 동기 전동기의 철손 분석 (A Research on Iron Loss of IPMSM with a Fractional Number of Slots Per Pole)

  • 서장호;이경표;정현교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.50-52
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    • 2008
  • In this paper, we investigated the iron losses in the rotor core of interior permanent magnet synchronous machine (IPMSM), which have distributed armature windings. From the analysis results, we can conclude that iron losses of rotor are definitely large at load condition if the number of slots per pole is fractional. Since the slot-pole combination may induce excessive heating, particular care should be necessary in design of PMSM for a high power rating application such as electric vehicles.

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농형회전자의 엔드링(End-ring)을 고려한 유도전동기 자계의 2차원적 동특성 수치해석 방법 (Numerical Analysis Method of 2-D Dynamic Characteristics of Magnetic Field in Squirrel Cage Induction Motor Considering End-ring)

  • 김영중;임달호
    • 대한전기학회논문지
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    • 제41권9호
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    • pp.1003-1012
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    • 1992
  • This paper presents and analysis method for designing a squirrel cage induction motor, which is aimed at analyzing the dynamic characteristics of magnetic field. This scheme is capable of estimating the effects of slot harmonics due to the rotation of rotor by utilizing Macro-airgap element combination, Voltage source treatment and Time difference algorithm. Furthermore, this strategy presents and approach which effectively compensates for end-ring of rotor. And direct convergence method is applied for considering a magnetic nonlinearity in core. In addition to the precision and the convergence study of algorithm, comparisons with experimental values prove the accuracy of this analysis method.

Full-pitched winding SRM에서의 상호(相互) 및 자기(自己) 인덕턴스의 산정에 관한 연구 (Study on Calculation of Mutual and Self-inductance in SRM with Full-pitched winding)

  • 백승규;이치우;정태욱;이일천;황영문
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 A
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    • pp.31-33
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    • 1996
  • A SRM develops its torque according to the inductance variation as the rotor position and the phase current. The variation of the inductance and the phase current plays an important role in output characteristics. Predicting and calculating the inductance is invaluable in the study of SRM. This paper suggests the estimation method of inductance as variation of phase current and rotor position considering magnetic saturation of motor core. This method is also applied to full-pitched winding SRM.

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영구 자석 Halbach 배열 가동자로 구성된 철심형 직선 영구자석 동기 전동기의 특성 해석 (Characteristic Analysis of Permanent Magnet Linear Synchronous Motor with Halbach Array and Iron Core)

  • 장석명;유대준;이성호;장원범;권정기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.72-74
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    • 2003
  • This paper presents a design and analysis solutions for the general class of iron-cored permanent magnet linear synchronous motor with Halbach (PMLSM). In our design and analysis, rotor consisting of permanent magnets rotor and slot less iron-cored coil stator are treated in a uniform way via vector potential. For one such motor structure, we give analytical formulas for its magnetic field, back electromotive force, inductance of winding coil, and trust force. We also provide performance comparisons of three types according to iron-cored and PM array.

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로봇 안구 구동용 구형 전자석 액추에이터 설계 (Design of A Spherical Electromagnetic Actuator for Robot's Eyeball)

  • 백두진;곽호성;김하용;김승종
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.668-673
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    • 2005
  • This paper proposes a simple actuator with a spherical rotor for robot's eyeball, which has two degrees of freedom. It features that both permanent magnets and coils are equipped in a stator and the spherical rotor with steps on its surface is driven by reaction of Lorentz force acting on the fixed coils. Such a structure is helpful to design a simple actuator and particularly suitable for a spherical actuator. Based on the FEM analysis, design parameters such as the sizes of core and permanent magnet, the width of step, coil turns and maximum current, are determined so as to maximize the torque and rotating angle. For the experimental verification of the feasibility, a prototype is manufactured and its operating characteristicsareinvestigated.

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The Design of Flux Barrier for Improvement of Demagnetization Endurance in BLDC Motor

  • Kim, Cheol-Min;Kim, Dong-Yeong;Cho, Gyu-Won;Kim, Gyu-Tak
    • Journal of Electrical Engineering and Technology
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    • 제9권6호
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    • pp.2181-2186
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    • 2014
  • Generally, the motor inside vehicle is exposed to highly ambient temperature and large vibration according to repeatedly starting and stopping for very short time. So, in this paper, the rotor shape design was performed to improve demagnetization endurance by considering the starting current of the Brushless DC (BLDC) Motor through the Finite Element Method(FEM). As a result, the partial irreversible demagnetization was occurred by starting current at the end of Permanent Magnets of the basic model. To solve this problem, the flux barrier design was performed and the flux on the rotor core was limited. Accordingly, demagnetization endurance and operating characteristics were improved.