• 대한기계학회논문집 C: 기술과 교육
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• 제3권2호
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• pp.141-148
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• 2015

본 연구에서는 진공 차단기(Vacuum circuit breaker)의 동적 특성을 모사하기 위해 리커다인을 이용한 다물체 동역학 해석 모델이 개발 되었다. 진공 차단기는 VI(Vacuum interrupter)를 포함한 3 개의 주회로 부와, 구동 메커니즘을 포함한 기구부로 구성된다. 이 해석적 모델의 검증을 위해, 해석 결과와 실측을 통한 실험적 결과를 비교 하였다. 일반적으로, 원활한 사고 전류 차단을 위해서는 0.9~1.1m/s 의 차단속도(Opening velocity)가 필요하다. 차단 속도의 향상을 위해, 다구찌 기법을 이용하여 진공 차단기의 설계 변수 최적화를 수행하였다. 또한 향상된 차단기의 동적 특성을 검증하기 위해, 해석 결과와 개선된 샘플의 실험적 결과를 비교 분석 하였다.

• 수산해양교육연구
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• 제16권2호
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• pp.210-217
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• 2004

Cooling technology has been a vital prerequisite for the rapid, if not explosive, growth of the electronic equipment industry. This has been especially true during the last 20 years with the advent of intergrated circuit chips and their applications in computers and related electronic products. The purpose of this study is to develop a telecommunication equipment cooling system using a thermoelectric module combined with cooling fan. Thermoelectric module is a device that can perform cooling only by input of electric power. In the present study, the cooling package using the thermoeletric module has been developed to improve the thermal performance. The cooling characteristics of the electronic chip was placed into the subrack and it can be rapidly assembled or disassembled in the equipment rack. As a preliminary experiment, the cooling performances between a conventional way using a cooling fin and a proposed method applying the thermoelectric module was comosed and analyzyed. The cooling performance at a simulated electronic component packaging a thermomodule operated well.

• 한국안전학회지
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• 제29권4호
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• pp.54-60
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• 2014

This paper describes electric shock accidents on a 4.16 kV class circuit breaker for power plant. Electric shock accidents mostly involve damage of human life, in comparison with electrical fire, rate of human death tend to be higher in electric shock accidents. Specially, in a high voltage facilities rate of human death comprised about 43.7% by electric shock accidents. If electric shock accidents happen in a 4.16 kV class circuit breaker for power plant, then the power plant discontinue power production. Electric shock accidents in a power plant have a great ripple effect such as an electric power shortage. In this paper, we analyzed electric shock accidents on a 4.16 kV class circuit breaker for power plant. From the analysis results, we confirmed a cause of electric shock accidents on a 4.16 kV class circuit breaker, it happened by defect of interlock equipment or occurrence of breakdown between first feeder contactor and shielding plate. In order to reduce electric shock accidents on a 4.16 kV class circuit breaker, the power plant should consider improvement of interlock equipment and insulation of feeder contactor in circuit breaker.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.68.5-68
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• 2002

For the performance test of rechargeable electric tools, it is necessary to test under the same condition as the actual operation condition. They are necessary to control the load torque and to acquire the test data with a computer, and it should be convenient to fix the tool on the test equipment for rechargeable electric tools. It consists of torque loading parts, sensing parts and control software. Two hysteresis brakes, connected serially with flexible coupling, were applied to control the load for the test. The sensing part consists of a torque sensor, a rpm detector and a power analyzer. The torque and the rpm were measured in order to calculate the output of the rechargeable electric...

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2507-2510
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• 2003

According as the industry develops recently, the import and export freight amount is increasing sharply, but physical distribution processing equipment ability had achieved conveyance, surge and setup of physical distribution by human's labor ability. But, inefficiency is indicated in operation of harbor and bay warehouse or physical distribution storage equipment because is ceilinged the processing physical distribution amount and the efficiency in physical distribution processing by these labor ability. Treatise that meet on these request proposes soldier warehouse physical distribution processing system that apply Vision System.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1103-1104
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• 2006

This paper is described about the test equipment of fraction motor for electric train. This test equipment was able to perform the performance test of traction motor which was operated in Korea. We explain performance and function of test equipment. In order to check the performance of test equipment, we conducted the performance test with 200 kW and 1100 kW traction motor.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.233-236
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• 2000

A portable equipment that measures a current and voltage waveform of power transmission lines is pro-posed. In the equipment, the current and voltage, respectively, are detected by a loop coil and a capacitor clamped around the power lines. The detected data is transmitted by an FM wave to the receiver on the ground station. Since the receiver is isolated from the power lines, we do not require high potential insulators for the measurement of current and voltage. The proposed equipment is therefore, small-sized, light, and low in the cost of production. Experimental results presented here show that the equipment can monitor the current flowing in single wire over a ground plane and the potential of the wire.

• 항공우주시스템공학회지
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• 제15권4호
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• pp.47-56
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• 2021

In the management of aged aircraft, used avionics equipment is replaced with new ones to improve the performance and extend the life cycle of the aircraft. In this case, considering airworthiness, it is necessary to check whether the aircraft has sufficient electricity in the electric generator or the electrical distribution system, in accordance with the maximum electricity consumption of the new avionics equipment. Accordingly, this paper reviews a few airworthiness standards and guidelines associated with the electrical load analysis when an avionics equipment is upgraded in an aged aircraft, and proposes an optimization method for the electrical load analysis. In addition, it verifies the validity of the proposed method via the QFD theory, and is currently available for upgrading the performance of aged aircraft.

• 통상정보연구
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• 제10권4호
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• pp.277-298
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• 2008

This study develops the market attractiveness assessment model and draws the strategic target markets and their corresponding exporting strategies through identifying the market positions in the dimensions of market attractiveness scores and market positional strength to achieve the innovative export promotion of Korean heavy electric industry and the resulting improvement and reversal of comparative-disadvantage position. In chapter 2, we analyze the stages of selecting target markets, the constructs and their measure variables of market attractiveness models, and the components and strategic policy implications of directional policy matrix. And in chapter 3, we identify the comparative advantage positions of Korean heavy electric industry in the global market through analyzing its trade structure, trends, balance, ratio-balance, and specialization index by the item and the region respectively. We find that the Asia/Pacific region is the most attractive export market of the Korean heavy electric equipment industry, the following important strategic target markets are the America, MENA, CIS/East Europe Regions in the order of their attractiveness and competitive position dimensions. In the mean time, the sub-Sahara Africa and West Europe region is shown to be the long-run-viewpoint target market requiring the innovation or divest strategies owing to their low attractiveness and the low market share of Korean exports.

• Journal of Magnetics
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• 제22권1호
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• pp.43-48
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• 2017

In order to detect the current flowing through concealed conductor, this paper proposes a new method based on derivative method. Firstly, this paper analyzes the main peak characteristic of the derivative function of magnetic field generated by a current-carrying conductor, and a relationship between the current flowing through the conductor and the main peak of the derivative function is obtained and applied to calculate the current. Then, the method is applied to detect the conductor current flowing through grounding grids of substations. Finally, the numerical experimental and field experiment verified the feasibility and accuracy of the method, and the computing results show that the method can effectively measure the conductor current of grounding grids with low error, and the error is within 5 %.