• Journal of Power Electronics
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• v.17 no.3
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• pp.835-847
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• 2017

A transmitting coil with an optimal topology and number of turns can effectively improve the performance of the wireless power transfer (WPT) systems for endoscope robots. This study proposes the evaluation parameters of the transmitting coils related to the performance of the WPT system to standardize the design of the transmitting coils. It considers both the quality factor of transmitting coils and the coupling factor between the two sides. Furthermore, an analytical model of transmitting coils with different topologies is built to exactly estimate the evaluation parameters. Several coils with the specified topologies are wound to verify the analytical model and the feasibility of evaluation parameters. In the case of a constant power received, the related evaluation parameters are proportional to the transfer efficiency of the WPT system. Therefore, the applicable frequency ranges of transmitting coils with different topologies are determined theoretically. Then a transmitting coil with a diameter of 69 cm is re-optimized both theoretically and experimentally. The transfer efficiency of the WPT system is increased from 3.58% to 7.37% with the maximum magnetic field intensity permitted by human tissue. Finally, the standardized design of the transmitting coil is achieved by summing-up and facilitating the optimization of the coils in various situations.

• Electrical & Electronic Materials
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• v.8 no.4
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• pp.518-525
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• 1995

본 고에서는 Nb$_{3}$Sn 초전도선재의 대표적인 제조방법 및 원리 그리고 고자장마그네트 설계시 중요한 요소인 Nb$_{3}$Sn의 자장중 초전도특성 및 기계적특성 등에 대하여 고찰하고자 한다. 또한 Nb$_{3}$Sn 초전도선재의 응용분야로서 몇가지 대표적인 예를 들어 현재 세계적으로 활발하게 진행되고 있는 선진국의 고자장 초전도마그네트와 관련된 연구개발동향을 소개하고자 한다.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 1999.02a
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• pp.65-68
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• 1999

The major deisng parameters that are considered in this paper are: 1) EMF according to width of field coil. 2) EMF according to magnetic shield length. Because of superconducting generator (SG) is actually and air cored machine with its rotor iron and stator iron teeth having been removed. In this case, the desing of the SG must be based on the 3D analysis of the magnetic field. This study presents an effective armature winding type with 3D FEM(Finite Element Method), and compares analyzed and measured results.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.65-67
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• 2004

In this paper, we Present two-dimensional (2-D) analytical model for predicting the magnetic field characteristic of slotless permanent magnet bushless motors. Results from the model are compared to those deduced from 2-D finite element analyses(FEA). It is shown that the radial magnetization and the parallel magnetization of permanent magnet can have flux density on coil, airgap and permanent magnet's surface.

• Journal of the Korean institute of surface engineering
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• v.27 no.6
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• pp.327-334
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• 1994

This work concerns a research for helicon wave plasma generators with applications to materials pro-cessing. For this end, helicon wave plasma source has been designed, constructed and tested. High density plasma was successfully produced and diagnosed with Langmuir probe. The measured maximum plasma de-nsity in this work was $10^{11}cm{-3}$ with 295 gauss of magnetic field and electron temperature was about 3.5eV. The uniformity of plasma densities in the radial direction was excellent with 160 gauss of magnetic field on the cross section which is 10cm apart from the edge of the exciting coil.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.89-92
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• 1996

In this paper, we mention the study on the sensing function of amorphous magneto- striction wire with about 125${\mu}{\textrm}{m}$$\Phi$ in diameter. The wire in fabricated by using injection and quenching method under the high speed rotating water flow. The wire\`s compotion is (Fe$_{75}$ $Co_{25}$)$_{77}$Si$_{8}$B$_{15}$ , and generates sharp Matteucci voltage by large Barkhausen jump effect even the weak magnetic field. In this study, we don\`t use pick-up coil. Instead, we apply external magnetic field of 3.6Oe in the direction orthogonal to the wire. Then, we detect Matteucci voltage of 1.lmV to both side of 20cm amorphous-wire. Thus, we find that the fabricated wire has the function necessary as the high sensitive sensor material.l.al.l.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.817-818
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• 2006

A 2.0T class HTS conduction cooled magnet was designed. Designing of magnet shape was performed through two steps. First step is to find a basic cross section for minimize the amount of conductor used and second step to optimize the coil shape to satisfy the magnetic field homogeneity. The magnetic fields was analyzed with FEM and the critical current value of magnet was also expected with the result of field analysis and the Ic to B curve of Bi-2223 HTS tape.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.179-180
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• 2018

자계 검출 센서는 여러 가지 종류가 있으나 벽면에 흐르는 미소 자계 및 차폐 전선에서 검출이 가능한 구조는 초전도 양자 간섭 소자(SQUID)가 주로 사용되지만 가격 및 물성 재료 특성으로 인하여 특수 용도로 사용되고 있다. 이에 본 연구에서는 전선으로부터 발생되는 저주파 자장을 검출할 수 있고 휴대성 및 가격이 저렴한 구조인 코일형 자계측정기를 개발하기 위해 자기 코어 및 코일 Turn수 변화에 따른 자계 검출 감도를 조사하여 최적의 구조를 설정하였다.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.34-36
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• 1998

In these days the hybrid interrupters are widely used for medium voltage class circuit breakers. In the design of the hybrid interrupter, the shape of the short-circuit ring is one of the most important design parameters. Recently the investigation into the phase difference between arc current and magnetic field due to the shape variation of the short circuit ring has been conducted. In this paper, the results of eddy current analyses in the hybrid interrupter and test result are presented.

• Journal of Magnetics
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• v.18 no.3
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• pp.255-259
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• 2013

In this paper a new coupling method for efficient and simple analysis of single phase induction motor is presented. The circuit representation of both the stator winding and each conducting rotor loop (composed of rotor bar and end ring segment) is used in conjunction with the distribution of magnetic flux linkage instead of inductance matrix. The flux linkage is calculated using air-gap flux density distributions driven by unit currents in the stator windings and rotor bars. The field distribution of one turn of a coil is calculated by FEM and the result is used to calculate total flux linkage by employing a coordinate transformation. The numerical results give good agreement with prior literature. The method is particularly effective in analyzing the effect of the number of rotor bars.