• 전기학회논문지
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• 제60권5호
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• pp.955-964
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• 2011

In renewable energy system such as flywheel energy storage system, wind power and solar power, the motor/generator is the important key for offering the electric energy to the electric loads. For example, the heavy and large flywheel is rotated by electromagnetic torque of pemanent magnet synchronous motor (PMSM) and, in case of a breakdown of electric current, the PMSM used as generator supplies electric energy for the various electric utilities using mechanical rotation energy of the flywheel. Thus, design of a motor/generator should be performed in effort to reduce cogging torque and electromagnetic loss for high efficiency. In our paper, a slotless permanent magnet synchronous motor/generator (SPMSM/G) with output power 15kW at the rotor speed 18000rpm is designed from electromagnetic analysis and dynamic performance analysis. In analytical approach, design parameters such as back electro-motive force (back EMF), inductance and electromagnetic torque are derived from analytical method which is one of the electromagnetic analysis method. And using the design parameters, this paper deal with system design considering the driving characteristics and electric load in required power. Finally, the analytical results are verified by the experiment and finite element method (FEM).

• 한국전자파학회논문지
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• 제19권7호
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• pp.791-799
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• 2008

본 논문에서는 $DC{\sim}18\;GHz$에서 동작하는 GTEM 셀 설계를 위한 전자파 모델링과 회로망 해석 기법을 제시하였다. GTEM 셀의 동축선 입력 급전부의 모드 변환기, 전송선 길이가 5미터인 확장형 사각 동축선 그리고 전송부 동축선의 전류와 입력단으로부터 입사되는 전자파를 정합시킬 수 있는 종단 부하로 구성되는 3차인 전자파 수치 해석 모델을 제시하였다. GTEM cell의 급전부, 전송선부, 종단 부하부에 대한 등가 회로망 모델을 제시하였으며, 이를 이용하여 전자파 수치 해석 모델에서 구해진 산란 계수로부터 GTEM cell의 성능 평가 지수인 입력 반사 계수를 계산할 수 있도록 하였다. $DC{\sim}18\;GHz$에서 동작하는 $5.0{\times}2.5{\times}1.7\;m$ 크기의 GTEM cell을 설계, 제작, 성능 평가하여 제안한 기법의 효용성을 입증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.520-522
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• 2005

This paper presents the design and analysis of the electromagnetic system such as jumping ring system. Also, we study the characteristics of dynamics for system with initial parameter. For the propose of system control,, first, we simulate the MATLAB tool solving coupled differential equations with electric parameter, inductance and mutual inductances. Therefore, we design a jumping ring system using design results, implement, and analyze the jumping ring system real situation. For the near time, we present a control process, and compare of real system and software technique.

• ETRI Journal
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• 제40권4호
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• pp.546-553
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• 2018

Since the Gyeongju earthquakes in 2016, there have been increased research interests in the areas of seismic design, building collapse, and rescue radar applications in Korea. Ground penetrating radar (GPR) is a nondestructive electromagnetic method that is used for underground surveys. To properly design ground penetrating radar that detects buried victims precisely, it is important to study electromagnetic wave propagation channel characteristics in advance. This work presents an electromagnetic propagation environment analysis of a trapped victim for GPR applications. In this study, we develop a realistic collapse model composed of layered reinforced concrete and a victim positioned horizontally. In addition, the effects of rebars and the distance between the radar antenna and target are investigated. The numerical analysis presents the electromagnetic wave propagation characteristics, including amplitude loss and phase difference, in the 450-MHz and 1,500-MHz frequency band, and it shows the electric field distribution in the environment.

• 한국전자파학회논문지
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• 제11권5호
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• pp.839-848
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• 2000

본 논문은 전자파 장해 및 복사내성 측정에 사용되는 전자파 무반사실의 대용 방법으로 활용될 수 있는 전자파 잔향실의 전자기장 특성에 관하여 연구하였다. 체적이 동일한 직사각형 및 삼각형 구조의 잔향실 내부 필드균일성을 확보하기 위하여 Shroeder diffuser 방식을 적용하였으며, FDTD(Finite-Difference Time-Domain) 방법을 사용하여 잔향실 내부의 필드 특성을 조사하였다. 앞에서 언급한 두 가지 형태의 잔향실 내부에서 필드 특성을 조사하기 위해 시험공간 내의 75% 샘플을 가지고 분석하였다. 직사각형 잔향실의 경우 최대 $\pm$3dB, 삼각형 잔향실의 경우 최대 $\pm$4.4dB 내의 tolerance를 나타내었으며, 또한 직사각형 잔향실의 경우 편파에 대해서도 독립적이라는 결과를 얻을 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.118-120
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• 2007

This paper deals with the vibration analysis of characteristics for BLDC motor by electromagnetic exciting force. Vibration analysis of electric machine is mainly divided into mechanical and electrical approach. However, it need to execute coupling analysis of mechanical and electrical computation because the vibration sources have relation to each other. Magnetic fields is calculated from Maxwell stress method with electromagnetic finite element method. And magnetic radial force is calculated from previous magnetic fields. With coupled electromagnetic and structure finite element, the vibratory behavior between the phase commutation advancing technique and pulse-width control is investigated in single phase brushless dc motor.

• 전기학회논문지
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• 제59권2호
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• pp.318-327
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• 2010

This paper deals with analysis on dynamic characteristic and circuit parameter of linear switched reluctance motor by electromagnetic analytical method. Above all, using space harmonic method, which is electromagnetic method, the air-gap flux density is analyzed in the both align and unaign positions, and the inductance profile, force characteristic and resistance per phase are calculated by means of the process. The validity of the analyzed results are demonstrated by the finite element method(FEM) and manufacture of the prototype machine. Second, the dynamic simulation is analyzed by the use of circuit parameters derived from analytical method, and the operating system of the prototype machine is manufactured to demonstrated the validity of simulation analysis. As a result, it is considered that the characteristic equation suggested in this paper will contribute to the design, analysis and application of LSRM.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.1020-1023
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• 2005

The fluid flow and thermal analysis were carried out by using the finite element program, Ansys. In analysis process, a electromagnetic analysis was accomplished. In afterwards, Fluid and thermal analysis was done. Fluid flow and heat could be produced by electromagnetic pump. In other words, A magnetic field which electromagnetic pump generates influences Liquid Material(Al alloy). This paper calculates the fluid flow and temperature distribution according to time. Using material is Al alloy(A356).

• Journal of electromagnetic engineering and science
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• 제6권4호
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• pp.229-234
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• 2006

This paper presents an advanced method of simulation for EM(electromagnetic) environment that affects on mobile receivers. A new calibration algorithm in the process of simulation is introduced. With a proposed calibration method, the time required for simulation is reduced and this makes it possible to simulate a near-real time EM environment in a shielded anechoic chamber. EM environment data acquisition and logging techniques with GPS for simulation were developed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.549-552
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• 2003

The electrical current generated by heart creates not only electric potential but also a magnetic field. We have observed electrophysiological phenomena of the heart by measuring tangential components of magnetocardiogram(MCG) using 61 channel superconducting quantum interference device(SQUD) system. In this paper, we developed a new analysis method, which is based on the theory of electromagnetic field. We show some differences of the current direction between the normal MCG and the abnormal(ischemic heart disease) MCG.