• 전력전자학회논문지
• /
• 제8권4호
• /
• pp.344-350
• /
• 2003

본 논문에서는 스위치드 릴럭턴스 모터의 새로운 회전자 초기 위치 추정법을 제안한다. 회전자의 위치검출을 하기 위하여 서치 코일을 사용하는 경우 센서비용감소, 부피감소, 강인성 증대, 사용범위의 확대 등 많은 장점이 있다. 그러나 모터의 회전자가 초기에 회전하지 않기 때문에, 서치코일에 유기되는 기전력이 존재하지 않아 회전자의 초기 위치검출에 어려움이 있었다. 본 논문에서는 유클리디안 제곱거리(Squared Euclidean Distance)를 사용하여 초기에 회전자가 정지해 있을 경우에도 회전자의 위치를 정확하게 추정하는 방법을 제시하였다. 이를 위하여 시뮬레이션을 실시하였고 이를 토대로 실험한 결과 정확한 초기 회전자 위치를 추정함으로써 본 논문에서 제시한 방법의 타당성을 검증하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제54권10호
• /
• pp.461-469
• /
• 2005

In this paper, a double-excitation type single sheet tester is developed to measure the magnetic characteristics of the electrical steel sheets. The developed system has the uniform magnetic field area of 20$\times$20mm$^{2}$, and can be applied to the measurement of the magnetic characteristics of the Non-oriented and Grain oriented electrical steel sheets. In the developed system, the magnetic flux density and magnetic field intensity are measured by using B-coil and H-coil, respectively. The B-coil has 1 turn search coil for each direction, and H-coil has 640 and 640 turns for rolling direction and transverse direction on the Im thickness Glass-Epoxy basement, respectively. Through experiments, it Is shown that the system can measure the magnetic characteristics up to 1.87 of magnetic flux density in the rolling direction in case of the Grain oriented electrical steel sheet. The measured results are compared with those measured in Okayama university, .Japan.

• 전력전자학회논문지
• /
• 제7권6호
• /
• pp.537-545
• /
• 2002

본 논문에서는 스위치드 릴럭턴스 모터의 새로운 회전자 위치 검출법을 제안한다. 기존의 위치센서의 약점을 보완하기 위해 위치 검출 방법의 저 비용과 강인성에 관심을 갖고, 시변 쇄교자속에 의해 토로이달 SRM의 내부에 장착된 서치 코일에 유기되는 전압 파형을 이용하여 위치 검출을 시도하였다. 서치 코일에서 유기되는 전압 파형이 회전자의 위치정보를 포함하고 있으므로, 이를 이용해 회전자의 특정위치를 검출하고 적절한 상을 여자시킴으로써 SRM을 구동할 수 있게 된다. 실험을 통하여 서치코일만을 이용하여 토로이달 SRM을 구동시킨 결과와 엔코더를 사용하여 구동시킨 결과와 비교함으로써 본 논문에서 제시한 방법의 타당성을 검증하였다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
• /
• pp.196-200
• /
• 2004

This paper presents a new method of detecting rotor position in Toroidal Switched Reluctance Motor(TSRM). In this paper, low cost and robust characteristics of rotor position detection method are focused in order to compensate for disadvantage of general sensors. Search coils wound through the hole of the stator poles are used for detection of the rotor position in TSRM. Rotor position detection is achieved through electromotive force patterns induced by time-varying flux linkage in the search coils and then adequate phase is excited for drive. The initial rotor position estimation method is also described. The validity of the method is verified by experimental results.

• 한국초전도학회:학술대회논문집
• /
• 한국초전도학회 2009년도 Korea Superconductivity Society Meeting 2009
• /
• pp.98-98
• /
• 2009

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2005년도 동계학술연구발표회 및 2차 아시안포럼
• /
• pp.48-50
• /
• 2005

• 조명전기설비학회논문지
• /
• 제21권3호
• /
• pp.27-34
• /
• 2007

농형유도전동기에서 회전자 도체의 고장은 전동기 성능에 나쁜 영향을 미친다. 본 논문에서는 이와 같은 고장유무를 수치해석적 방법으로 분석하는 방법을 제안하였다. 정상이 아닌 회전자 도체가 있는 농형유도전동기의 회전자에서 고장에 따라 나타나는 특징적인 파형을 수치 해석적 방법으로 분석하였다. 이와 같은 방법으로 정상적인 도체와 고장 도체가 있는 경우의 특징을 분석함으로써 고장의 유무, 상태를 파악할 수 있다. 회전자 고장진단 실험 장치를 제작하고 실험을 통하여 제안한 방법의 타당성과 유용성을 확인하였다.

• Journal of Magnetics
• /
• 제21권1호
• /
• pp.57-60
• /
• 2016

Non Destructive Testing (NDT) methods that are capable of detecting the wall thinning and defects through insulation and cladding sheets are necessary. In this study we developed a Pulsed Eddy Current (PEC) system to detect wall thinning of ferro magnetic steel pipes covered with 95 mm thick fiber glass thermal insulator and shielded with aluminum plate of thickness 0.4 mm. In order to confirm the thickness change due to wall thinning, two different sensors, a hall sensor and a search coil sensor were used as a detecting element. In both the cases, the experimental data indicates a considerable change in the detected pulse corresponding to the change in sample thickness. The thickness of the tube was made to change such as 2.5 mm, 5 mm and 8 mm from the inner surface to simulate wall thinning. Fast Fourier Transform (FFT) was calculated using window approach and the results were summarized which shows a clear identification of thickness change in the test specimen by comparing the magnitude spectra.

• 한국전기전자재료학회논문지
• /
• 제14권11호
• /
• pp.912-916
• /
• 2001

Fluxmeter is a measuring instrument the magnetic flux intensity by means of an integration of the voltage induced to a search coil to unit time. It also is required to a precise integrator since the voltage induced to a search coil has a differential value of the flux ${\Phi}$ to unit time. In this study, a bias current which is a main problem of the integrator in a drift troublesome depending on the temperature of a FET is investigated. We have confirmed that the temperature dependence of both the bias current of a integrator using the FET and the reversal saturated current of the minor carrier in a P-N junction of a semiconductor were the same. The property of a commercial integrator goes rapidly down with increasing temperature. The bias current of a FET is increased twice as much with 10$^{\circ}C$ increment. As a result, the low drift integrator could be developed by setting the lower temperature up with a pottier device.

• 한국정밀공학회지
• /
• 제30권1호
• /
• pp.47-52
• /
• 2013

In order to operate a search and rescue robot in hazardous area, the robot requires high mobility and adaptable locomotion for moving in unpredictable environments. In this paper, we propose the deformable soft wheel robot that can produce three kinds of driving modes; caterpillar driving mode, normal wheel driving mode, legged-wheel driving mode. The robot changes its driving mode as it faces the various obstacles such as a small gap, stairs etc. Soft film and composite materials are used for fabrication of deformable wheel structure and Shape Memory Alloy (SMA) coil spring actuators are attached on the structure as an artificial muscle. Film lamination and an composite manufacturing process is introduced and the robot design is required to be modified and compromised to applying the manufacturing process. The prototype is developed and tested for verifying feasibility of the deformable wheel locomotion.