• 제목/요약/키워드: Air-gap

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알루미늄 소결재를 이용한 흡음 특성 연구 (Study of sound absorption characteristics using the sintered aluminium plate)

  • 노대호;김재수;윤진국;강현주;신종철;김원용
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.1071-1076
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    • 2002
  • The purpose of this paper is to examine sound absorption characteristics of sintered Al(aluminum) plate. Comparison between experiment and theoretical analysts by using empirical formula are made. Based on comparison. it is found that Voronina model gives more reasonable explanation for sound absorption characteristics of sintered Al plates. Effect of air gap with varying the thickness of plates are also investigated, which concludes that the air gap generally increase absorption but for too thick thickness of Al plates. Al plates with air gap shows 0.85∼0.9 of NRC(Noise Reduction Coefficient) measured in reverberation room. which is comparable to glass wool. Comparison between normal and random Incident absorption shows that random incident absorption is higher than normal incident absorption.

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슬롯 고조파를 고려한 전기기계 공극자계의 해석 방법에 관한 연구 (A study on the method of Air gap field Analysis considering slot harmonics in the electric machine)

  • 임달호;김생수;김영중;윤상백
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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    • pp.33-36
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    • 1987
  • Is this study it is proposed a method which is able to compute preciously using time-difference method to the air-gap magnetic field in electric machines take into account of eddy current induced. The air-gap magnetic field has slot harmonics which are due to the structure of machines and the shape of slot harmonics varies with the related positions of slots when the rotor moves. Accordingly, considering the influence of slot-harmonics, we coupled macro-air-gap element with first-order triangular elements in domain and used direct-convergence method for magnetic saturation.

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자기부상열차 고가 선로 구조특성에 따른 부상공극 응답 (Air Gap Change of a Maglev Vehicle at the Moment a Linear Induction Motor Runs)

  • 신현재;한형석;이종민;노규석
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집
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    • pp.1213-1217
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    • 2009
  • The air gap between electromagnet and guiderail in an EMS-type Maglev vehicle must be maintained within an allowable deviation by controlling the voltage on the magnet. In this type of vehicle, the air gap response is strongly dependent on the structural characteristics of the elevated guideway, such as stiffness, damping and mass. For this reason, the dynamic interaction between the vehicle with electromagnets and the elevated guideway must be understood to ensure safe running. The response of the air gap to guideway characteristics such as mass, stiffness, and damping are analyzed through vehicle tests over different guideways. Through such tests, the design requirements for Maglev vehicles and elevated guideways can be established, improving levitation stability.

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Air-Gap 마이크로스트립 안테나의 공진주파수 이동에 관한 연구 (Resonant Frequency Variation of Air-Gap Microstrip Antenna)

  • 김영훈;오승재;임승혁;여동훈;이종덕;송준태
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.1480-1482
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    • 2000
  • This paper investigated that resonant frequencies of Air-Gap microstrip patch antenna were tunable when piezoelectric material were used as the antenna substrates. The resonant frequencies of the air-gap antenna using the piezoelectric substrate were able to be controlled by applied AC voltage. The frequency variation of the antenna was great when PZT were applied voltage of the resonant frequency.

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ZnO를 이용한 air-gap 형태의 FBAR 소자 제작에 대한 연구 (A study of air-gap type FBAR device fabrication using ZnO)

  • 박성현;이순범;신영화;이능헌;이상훈;추순남
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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    • pp.1414-1415
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    • 2006
  • Air-gap type film bulk acoustic wave resonator device using ZnO for piezoelectric layer and sacrifice layer, deposited by RF magnetron sputter with various conditions, fabricated in this study. Also, membrane$(SiO_2)$ and top and bottom electrode(both Al) of piezoelectric layer deposited by RF magnetron sputter. Using micro electro mechanical systems(MEMS) technique, sacrifice layer removed and then air-gap formed. The results of each process checked by XRD, AFM, SEM to obtain good quality device.

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매입형 영구자석 전동기에서 무부하시 공극 자속밀도 분포에 대한 Slot-Opening Effect를 고려한 보조 모델 (Assistant Model For Considering Slot-Opening Effect on No-load Air-gap Flux Density Distribution in Interior-type Permanent Magnet Motor)

  • 방량;김도진;홍정표
    • 전기학회논문지
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    • 제60권4호
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    • pp.759-765
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    • 2011
  • This paper proposes an effective assistant model for considering the stator slot-opening effect on air gap flux density distribution in conventional interior-type permanent magnet (IPM) motor. Different from the conventional slot-opening effect analysis in surface-type PM (SPM) motor, a composite effect of slot-opening uniquely existing in IPM motor, which additionally causes enhancement of air gap flux density due to magnet flux path distortion in iron core between the buried PM and rotor surface. This phenomenon is represented by a proposed assistant model, which simply deals with this additional effect by modifying magnetic pole-arc using an effective method. The validity of this proposed analytical model is applied to predict the air gap flux density distribution in an IPM motor model and confirmed by finite element method (FEM).

Examination of Efficiency Based on Air Gap and Characteristic Impedance Variations for Magnetic Resonance Coupling Wireless Energy Transfer

  • Agcal, Ali;Bekiroglu, Nur;Ozcira, Selin
    • Journal of Magnetics
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    • 제20권1호
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    • pp.57-61
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    • 2015
  • In this paper wireless power transmission system based on magnetic resonance coupling circuit was carried out. With the research objectives based on the mutual coupling model, mathematical expressions of optimal coupling coefficients are examined. Equivalent circuit parameters are calculated by Maxwell software, and the equivalent circuit was solved by Matlab software. The power transfer efficiency of the system was derived by using the electrical parameters of the equivalent circuit. System efficiency was analyzed depending on the different air gap values for various characteristic impedances. Hence, magnetic resonance coupling involves creating a resonance and transferring the power without radiating electromagnetic waves. As the air gap between the coils increased the coupling between the coils were weakened. The impedance of circuit varied as the air gap changed, affecting the power transfer efficiency.

Analytical Investigation on Fundamental Electrical Characteristics of Large Air-gap Superconducting Synchronous Machine

  • Yazdanian, M.;Elhaminia, P.;Zolghadri, M.R.;Fardmanesh, M.
    • Journal of Magnetics
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    • 제18권3호
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    • pp.260-267
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    • 2013
  • In this paper a general 2-D model of a large air-gap synchronous machine either with non-magnetic or magnetic core rotor is investigated and electrical characteristics of the machine are analytically calculated. Considering the general model, analytical equations for magnetic field density in different regions of the large air-gap machine are calculated. In addition, self and mutual inductances in the proposed model of the machine have been developed, which are the most important parameters in the electromagnetic design and transient analysis of synchronous machines. Finite element simulation has also been performed to verify the obtained results from the equations. Analytical results show good agreement with FEM results.

단상 영구자석 동기 전동기의 비대칭 공극 구조를 고려한 회전자 초기 자극 검출 기법 (Rotor Initial Polarity Detection Method of Single-Phase PMSM Considering Asymmetric Air-Gap Structure)

  • 서승우;황선환;박종원;김용휴
    • 전력전자학회논문지
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    • 제27권1호
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    • pp.80-83
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    • 2022
  • This paper proposes an initial rotor polarity detection algorithm of a single-phase permanent magnet synchronous motor (SP-PMSM) related to stable open-loop starting for sensorless operation. Generally, the SP-PMSM needs an asymmetric air-gap structure to can avoid the initial starting failure at zero torque point. Therefore, the rotor polarity information can be obtained by using the DC offset current direction of a stator current through a high frequency voltage injection into an SP-PMSM with an asymmetric air gap. In this paper, the proposed rotor initial polarity detection algorithm is verified through several experimental results.

실리콘 러버 소켓의 구조 변경을 통한 신호 전달 특성 향상 (Enhancement of Signal Transmission Characteristics Using Structural Changes in Silicone Rubber Socket)

  • 김선아;김문정
    • 반도체디스플레이기술학회지
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    • 제23권1호
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    • pp.104-109
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    • 2024
  • In this paper, we propose structures of a socket that can improve signal transmission characteristics compared to the existing silicone rubber socket. A coaxial rubber socket was proposed to improve signal distortion due to electromagnetic interference between signal lines. And an air gap rubber socket was proposed to improve the degradation of reflection characteristics due to high dielectric constant. Using a 3D electromagnetic field simulator, the S-parameter and crosstalk of the three sockets were compared and the signal transmission characteristics were analyzed. In both coaxial rubber socket and the air gap rubber socket, S-parameter and crosstalk were improved compared to the silicone rubber socket. Among them, the air gap rubber socket was the best for S-parameter, and the coaxial rubber socket was the best for crosstalk.

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