• 대한기계학회논문집B
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• 제38권6호
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• pp.539-545
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• 2014

실리콘 태양전지의 실버 전극과 이미터층 사이의 접촉 비저항은 원형 접촉 비저항 측정법과 선형 비저항 측정법을 이용하여 계측되어 왔다. 원형 접촉 비저항 측정법은 누설 전류를 차단하기 위한 메사 에칭 등의 부가적인 공정이 요구되지 않는 장점이 있으며, 선형 접촉 비저항 측정법은 완성된 태양전지로부터 직접 샘플을 취득하여 측정을 수행할 수 있다는 장점이 있다. 본 연구에서는 이 두 가지 측정법들을 이용하여 실리콘 태양전지 전면 전극의 접촉 비저항을 계산하기 위한 저항값들을 측정할 때 수반되는 문제점들에 대한 비교연구를 수행하였으며, 선형 접촉 비저항 측정법이 실버 전극의 선폭과 두께에 따른 접촉 비저항 변화를 좀더 정확하게 묘사할 수 있는 요인에 대해 설명하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.2016-2018
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• 2002

An exact solution of the lossy linear tapered transmission line is derived. As its application, a simple design method of the quasi non-distortion lossy linear tapered transmission line in the time domain is described. A design example is presented to show the validity and usefulness of the method.

• Wind and Structures
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• 제31권6호
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• pp.509-522
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• 2020

Wind load is the principal cause for a large number of the collapse of transmission lines around the world. The transmission line is traditionally designed for wind load according to a linear equivalent method, in which dynamic effects of wind are not appropriately included. Therefore, in the present study, incremental dynamic analysis is utilized to investigate the stability behavior of a 400 kV transmission line under wind load. In that case, the effects of vibration of cables and aerodynamic damping of cables were considered on the stability behavior of the transmission line. Superposition of the harmonic waves method was used to calculate the wind load. The corresponding wind speed to the beginning of the transmission line collapse was determined by incremental dynamic analysis. Also, the effect of the yawed wind was studied to determine the critical attack angle by the incremental dynamic method. The results show the collapse mechanisms of the transmission line and the maximum supportable wind speed, which is predicted 6m/s less than the design wind speed of the studied transmission line. Based on the numerical modeling results, a retrofitting method has been proposed to prevent failure of the tower members under design wind speed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1543-1544
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• 2008

In this paper, we introduce a gaussian enveloped linear chirp signal that can change parameters for consideration of target material characteristics. Using the gaussian enveloped linear chirp signal, time-frequency domain reflectomety is able to detect fault location in power transmission line. we suggest design method of reference signal for power transmission line fault detection. This method is verified by locating fault in HIV low voltage power transmission line.

• ETRI Journal
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• 제32권3호
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• pp.395-405
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• 2010

A novel multiclassifier system (MCS) strategy is proposed and applied to a text-dependent speaker verification task. The presented scheme optimizes the linear combination of classifiers on an on-line basis. In contrast to ordinary MCS approaches, neither a priori distributions nor pre-tuned parameters are required. The idea is to improve the most accurate classifier by making use of the incremental information provided by the second classifier. The on-line multiclassifier optimization approach is applicable to any pattern recognition problem. The proposed method needs neither a priori distributions nor pre-estimated weights, and does not make use of any consideration about training/testing matching conditions. Results with Yoho database show that the presented approach can lead to reductions in equal error rate as high as 28%, when compared with the most accurate classifier, and 11% against a standard method for the optimization of linear combination of classifiers.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권10호
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• pp.523-529
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• 1999

In the case of the large power transformer, the grain-oriented material is usually used. So, to obtain more accurate results, anisotropy and non-linearity of the material must be considered. The Newton-Raphson(NR) method is generally used for analyzing these non-linear properties, but it consumes so much time, especially when the number of nodes is large or the shape of the model is complex. The transmission line modeling (TLM) method is successfully adopted to the analysis of non-linear properties with FEM, but it has not been adopted to the analysis of the anisotropic material. In this paper, the formulation of the TLM method considering anisotropy is developed and the adoption to the 3-phase transformer is presented.

• 한국전자파학회논문지
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• 제11권3호
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• pp.419-428
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• 2000

전송선 방정식을 이용하여 선형소자로 종단된 손실이 있는 다중 전송선에서의 누화(crosstalk)와 외부 전자파 에 의한 결합현상을 FDTD 기법으로 해석하였다. 표피효과에 의한 도체의 손실을 고려하여 해석할 경우 전송선 방정식에 컨벌루션 적분이 나타나게 되는데 컨벌루션 적분의 계산량을 줄이기 위해서 프로니(Prony) 방법을 이 용하였다. 또한 저항뿐만 아니라 인덕터나 커패시터로 종단된 다중 전송션을 해석하기 위해 상태변수 표현식 (state-variable formulation)을 이용하였다, TEM(Transverse Electromagnetic) 셀을 이용해서 다중 전송선에서의 누화와 외부 입사장에 의한 전자파 결합현상을 시간영역에서 측정하였고 이론적으로 구한 시율레이션 결과 와 비교하여 잘 일치함을 확인하였다. 또한 PCB와 같이 KSC 3340 TIV보다 상대적으로 손실이 큰 전송선 구조 인 경우 도체의 길이가 짧아도 손실을 포함해야 정확한 예측이 가능함을 확인하였고 저주파에서의 저항은 정상 시간 응답을 결정하고 고주파에서의 임피던스는 초기시간 응답을 결정함을 보였다.

• International journal of advanced smart convergence
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• 제8권2호
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• pp.155-161
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• 2019

We introduces a mobile robot that can navigate on a power transmission line arranged in bundled conductors. The designs of the proposed robot are performed for navigation on bundled conductors, and the navigation method for bundled conductors and obstacle avoidance are presented. The robot consists of 13 degrees of freedom (DOF) with a symmetrical structure for the left and right parts, including the four wheel joints. The navigation method is designed using a combination of three motion primitives such as linear motion of counterbalancing box, linear motion of robot arm, and rotational motion of wheel part. To examine the performance of the proposed robot, navigation simulations are conducted using $ADAMS^{TM}$. The robot navigations were simulated on obstacle environments that consisted of two- and four-conductor bundles. Based on the simulation results, the performance of the proposed robot was reviewed through the analysis of the trajectories of end-effectors. We confirmed that the proposed robot was capable of achieving optimal navigation on bundled conductors that included obstacles.

• 한국산학기술학회논문지
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• 제6권6호
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• pp.478-485
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• 2005

본 논문에서는 전하중첩법을 이용하여 다극성, 다도체 직류송전선의 주변 이온장을 해석하였다. 이와 관련한 알고리즘은 비선형 편미분 방정식으로 표현되어 매우 복잡하기 때문에 문제를 해석적으로 풀기가 매우 어렵다. 그래서 여기서는 다극성, 다도체 직류 송전선에 적용할 수 있는 컴퓨터 프로그램을 개발하였고 제안한 알고리즘의 타당성을 증명하기 위해 공간전하를 고려한 도체표면의 전계강도 및 코로나 전류밀도, 공간전하 밀도를 계산하였다.

• 대한전기학회논문지
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• 제37권5호
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• pp.272-281
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• 1988

The problem of optimal transmission system planning is to find the most economical locations and time of transmission line construction under the various constraints such as available rights-of-way, finances, the technical characteristics of power system, and the reliability criterion of power supply, and so on. In this paper the constraint of right-of-way is represented as a finite set of available rights-of-way. And the constructed for a unit period. The electrical constraints are represented in terms of line overload and steady state stability margin. And the reliability criterion is dealt with the suppression of failure cost and with single-contingency analysis. In general, the transmission planning problem requires integer solutions and its objective function is nonlinear. In this paper the objective function is defined as a sum of the present values of construction cost and the minimum operating cost of power system. The latter is represented as a sum of generation cost and failure cost considering the change of yearly load, economic dispatch, and the line contingency. For the calculation of operating cost linear programming is adopted on the base of DC load flow calculation, and for the optimization of main objective function nonlinear Branch-and-Bound algorithm is used. Finally, for improving the efficiency of B & B algorithm a new sensitivity analysis algorithm is proposed.