• 한국지능시스템학회논문지
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• 제15권1호
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• pp.24-29
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• 2005

일반적으로 다변수 계통에 대한 퍼지 제어에서 퍼지 규칙을 얻기가 어려워 입출력 사이의 페어링을 이용한 독립적인 단일 입력 단일 출력의 병렬 구조를 이용한다. 그러나, 결합되지 않은 입출력 변수간의 상호작용으로 제어 성능에 나쁜 영향을 준다. 특히, 강한 결합 특성을 가진 계통의 경우 제어 성능을 아주 저하시킨다. 본 논문에서는 이러한 상호작용에 의한 영향을 보상해주기 위해 상대 이득 행렬을 이용한 신경 회로망을 도입하였다 제안한 뉴로 퍼지 제어기는 역전파 알고리즘으로 학습되며 강호작용에 대한 결합강도를 자동으로 조정하여준다. 제안한 뉴로 퍼지 제어기의 성능을 200MW급 보일러 계통에 대한 컴퓨터 모의실험을 통해 입증하였다.

• 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.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.231-232
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• 2016

This paper investigates the design of multi-winding coupled inductor for minimum inductor current ripple. Based on the general circuit model of coupled inductor together with the operating principles of dc-dc converter, the relationship between the ripple size of inductor current and the coupling factor is derived under the different duty ratio. The optimal coupling factor of n-phase multi-winding coupled inductor which corresponds to a minimum inductor ripple current becomes -(1/n-1), i.e. a complete inverse coupling without leakage inductance, as the duty ratio of steady-state operating point approaches 1/n, 2/n, ${\cdots}$ or (n-1)/n. In an opposite manner, the optimal coupling factor value of zero, i.e. zero mutual inductance, is required when the duty ratio of steady-state operating point approaches either zero or one. Therefore, coupled inductors having optimal coupling factor can minimize the ripple current of inductor and inductor size.

• 전기전자학회논문지
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• 제23권1호
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• pp.306-309
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• 2019

Wireless charging is a technology of transmitting power through an air gap to an electrical load for the purpose of energy dissemination. Compared to traditional charging with code, wireless power charging has many benefits of avoiding the hassle from connecting cables, rendering the design and fabrication of much smaller devices without the attachment of batteries, providing flexibility for devices, and enhancing energy efficiency, etc. A transmitting coil and a receiving coil for inductive coupling or magnetic resonant coupling methods are available for the near field techniques, but are not for the far field one. In this paper, the wireless power transfer (WPT) circuit by using magnetic resonant coupling method with a resonant frequency of 13.45 Mhz for the low power system is implemented to measure the power transmission efficiency in terms of mutual distance and omnidirectional angles of receiver.

• Journal of electromagnetic engineering and science
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• 제18권1호
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• pp.13-19
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• 2018

Wireless power transfer (WPT) based on magnetic resonant coupling is a promising technology in many industrial applications. Efficiency of the WPT system usually depends on the tilt angle of the transmitter or the receiver coil. This work analyzes the effect of the tilt angle on the efficiency of the WPT system with horizontal misalignment. The mutual inductance between two coils located at arbitrary positions with tilt angles is calculated using a numerical analysis based on the Neumann formula. The efficiency of the WPT system with a tilted coil is extracted using an equivalent circuit model with extracted mutual inductance. By analyzing the results, we propose an optimal tilt angle to maximize the efficiency of the WPT system. The best angle to maximize the efficiency depends on the radii of the two coils and their relative position. The calculated efficiencies versus the tilt angle for various WPT cases, which change the radius of RX ($r_2=0.075m$, 0.1 m, 0.15 m) and the horizontal distance (y=0 m, 0.05 m, 0.1 m), are compared with the experimental results. The analytically extracted efficiencies and the extracted optimal tilt angles agree well with those of the experimental results.

• 전기학회논문지
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• 제61권3호
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• pp.384-393
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• 2012

Railroad signaling systems perform controlling the distance and routes between trains. Signaling methods on the wayside are to control passively the train speed by using signal flags which are installed on the wayside. ATS(Automatic Train Stop) device is used as the signaling method on the wayside in Korea. The ATS device is assistance equipment of engineers. Signal information is transmitted by combining mutual inductance between the wayside transmitter and on-board receiver. The wayside transmitter performs changing oscillation frequency according to the signal information. The on-board receiver performs controlling the train by receiving the frequency. Currently, the oscillation frequency on the on-board receiver is 78[kHz] in case of normal state. When the on-board receiver is over the wayside transmitter, the oscillation frequency is changed by capacitors of the wayside transmitter according to signal flags. In case of changing the oscillation frequency, the waveform is modified in the wayside transmitter and on-board receiver. This phenomenon is that other signals or communication frequency are included. In this paper, electric model between the wayside transmitter and on-board receiver is suggested and frequency response in the wayside transmitter and on-board receiver including other signals is estimated by the coupling coefficient. Also, the value of coupling coefficient is proposed to exclude other signals and demonstrated by using Matlab and PSpice program.

• 한국음향학회지
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• 제15권1호
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• pp.17-22
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• 1996

소나 시스템에 주로 사용이 되는 평면 배열형 음향 트랜스듀서는 수중에서 음을 방사하여 빔(beam)을 형성하게 된다. 이러한 빔은 트랜스듀서 진동체에서 발생하는 음향 출력이 공간상에 분포되어 일어난다. 따라서 방사 출력의 산출은 트랜스듀서의 성능 및 효율을 예측하는데 필요하다. 본 논문에서는 무한 배플에 고정된 9개의 음향 진동체를 모델로 선정하였다. 개별 진동체에서의 음향 방사량은 자기방사 및 상호방사의 조합으로 표현이 되며 전기적 등가회로 기법을 이용하여 진동체 상호간의 음향 간섭 영향을 고려하여 평면 배열형 음향 트랜스듀서 진동체의 방사 출력 예측 기법을 제안 하였다.

• Journal of electromagnetic engineering and science
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• 제5권3호
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• pp.122-125
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• 2005

This paper describes a design of a miniature patch antenna and its 4-channle array for 5.25 GHz wireless LAN band. Each patch element is designed for the low mutual coupling between each element and for the small size of the array antenna. The size of the each element is $7 mm{\times}14.5 mm{\times}5.6 mm$ and it satisfy IEEE 802.11a frequency band. It is arrayed for independent 4-channel operation. The total size of the array antenna is $35.6 mm{\times}52.5 mm{\times}5.6 mm$. The measured reflection coefficients and the radiation patterns of the fabricated antennas show the reasonable agreements with prediction.

• 자원환경지질
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• 제19권4호
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• pp.293-296
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• 1986

총상대지에서 수직공측루프에 대한 상호결합비의 새로운 관계식을 방정식 중의 0차 뱃셀함수를 1차로 변환함으로써 유도하였다. 이 관계식을 쓰면 $J_0$와 $J_1$ 두개의 필터대신 $J_1$필터만이 필요하게 되며, 계산시간이나 기억용량이 크게 절감된다. 본 논문에서는 3층구조 대지에 대한 상호결합비를 앤더슨의 필터로 구하였다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.347-352
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• 2005

Scan Element Pattern(SEP) and Scan Impedance(SI) concepts are used to analyze the characteristics of open-ended waveguide array, which is the representative phased array antenna element in C-band and X-band. Transmit SEP's are calculated for 15$\sim$15 subarray and SI's are obtained by applying periodic boundary conditions for a unit cell of the given array condition. CST's MWS and Ansoft's HFSS are utilized for each analysis. Some relations are reviewed between the two results, which are based on mutual coupling effects. For validation purpose, an 8$\sim$8 subarray is constructed and tested. Transmit SEP measured in MTG's far-field range shows good agreement with the calculated transmit SEP.