• Corrosion Science and Technology
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• v.18 no.4
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• pp.117-120
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• 2019

Considering the tendency of development of electrification vehicles, development and verification of new evaluation technology is needed because of new technology applications. Recently, as the battery package is set outdoors of an electric vehicle, such vehicles are exposed to corrosive environments. Among major components connected to the battery package, rust prevention of high-voltage cables and connectors is considered the most important issue. For example, if corrosion of high voltage cable connectors occurs, the corrosion durability assessment of using an electric vehicle will be different from general environmental corrosion phenomena. The purpose of this study is to investigate the corrosion mechanism of high voltage cable connectors of an electric vehicle under various driving environments (road surface vibration, corrosion environment, current conduction by stray current, etc.) and develop an optimal rust prevention solution. To improve our parts test method, we have proposed a realistic test method to reproduce actual electric vehicle corrosion issues based on the principle test.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.943-944
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• 2007

In this paper, the development and the test of 13.2kV/630A high-Tc superconducting fault current limiting coil are described. The fault current limiting coil made of Coated Conductor (CC) was fabricated with bifilar winding method for non-inductive characteristics and tested in the distribution power system level in Dec. 2006. In order to determine the length of the superconducting coil, applied voltage per unit length(V/m) was studied analytically and it was verified through experiments. For the volume minimization, the coil was designed with concentrical arrangement method. The short-circuit test was performed with the prospective fault current of asymmetrical 10kA whose maximum fault current was $30kA_{peak}$. In the test, the voltage drop and the current of the coil were measured and the resistance of the coil was obtained. Also, the temperature rise of the coil was calculated with the relationship between the resistance and the temperature of CC. In this paper, the experimental results are analyzed and compared with the simulation.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.294_295
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• 2009

Superconducting fault current limiter (SFCL) is an power device of a novel concept. While SFCLs generate no ohmic loss during the operation carrying normal currents, they can limit fault currents very fast making large impedance by their quench characteristics. In 2006, KEPCO has developed a distribution class hybrid type SFCL by a collaborative research project with LS industrial systems. The SFCL has merits in practical and economical points of view. In the SFCL, the superconductor just plays a role of a fault detector and the current limiting is completed by the other current limiting element made of normal metals throu호 the line commutation. As a result, the required amounts of superconductors can be reduced considerably. Consequently, the hybrid SFCL can be fabricated with small size and cost, maintaining perfect current limiting performance. Currently, KEPCO is carrying out a research project at Gochang power test center for the purpose of the verification test of the 22.9 kV/ 630 A class SFCL for the practical application in real grid. Through the project, a long term operational test and fault current test will be done. In this paper, the back ground of development and installation of the SFCL will be explained and the operation plan of the SFCL for the verification test is also introduced.

• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.348-355
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• 2024

A current source capable of stably supplying current as a measurement medium is required in order to measure and test important facilities that require large-scale measurement current, such as a control element drive mechanism control system(CEDMCS), in case of dismantling a nuclear power plant. However, it can provides only voltage power as a source, not current, although direct voltage controlled constant current source is essential to test major equipment. That kind of source is not available to supply stable constant current regardless of load variation. It is just voltage supplier. Developing current source is not easy other than voltage source. Very large-scale current source up to ampere class more than such ten times of normal current is inevitable to test above mentioned equipment. So, we developed large-scale current source which is controlled by input DC voltage and supplies constant stable current to object equipment according to this requirement. We measured and tested nuclear power plant equipment using given real site data for a long time and afforded long period load test, and then proved its validity and verification. The developed invetion will be used future installed important equipment measuring and testing.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.5
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• pp.195-201
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• 2006

Tower footing resistance and fault current division factor are important design factors for evaluation of the lightning performance of the transmission line and/or design of the grounding electrode system. The periodic measurement of those factors are also important to verify that the grounding performance of the towers has been maintained good. However, the direct measurement of those factors in operating or energized condition is very difficult because of many practical reasons, such as the difficulty of disconnecting overhead groundwires from the tower under test. With supports by GECOL (General Electricitiy Company of Libya), we had a special chance to conduct Fall-Of-Potential (FOP) test on the energized 220 kV transmission towers before and after disconnecting the overhead groundwires from the towers under test. In this paper, the FOP test results on the towers and the fault current division factors estimated from the comparision of the FOP tests with and without overhead groundwires were presented. The computer models for the FOP test simulations were also constructed to find that the simulated results agreed very well with the measured ones.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.367-370
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• 2000

It is shown that $I_{DDQ}$ testing is very useful for shipping fault-free CMOS ICs. However, test time of $I_{DDQ}$ testing is extremely larger than one of logic testing. In this paper, a new test input sequence generation methodology is proposed to reduce the test time of $I_{DDQ}$ testing. At first, it is Shown that $I_{DDQ}$ test time Will be denominated by charge supply current for load capacitance of gates whose output logic values are changed by test input vector application and the charge current depends on input sequence of test vectors. After that, a test input sequence generation methodology is proposed. The feasibility is checked by some experiments.riments.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.49-51
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• 2005

The saturation of transformer for short-circuit test suppress the peak current value during the test. And such phenomenon effect on the test results occasionally. This paper deals with the induction of the formula to restore the peak current value from the measured data.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.291-295
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• 2008

We have developed an evaluation technique for ratio errors of current transformer (CT) comparator by using the precise standard capacitors. By applying this technique for equivalent circuit of CT comparator evaluation system, we can obtain the calculated and measured ratio errors in the CT comparator. Thus we can evaluate ratio errors of CT comparator by comparing the calculated and measured ratio errors. Because this method requires only the standard capacitors, it is simple and easy method to reliability and accuracy maintenance of CT comparator. The method was applied to CT comparator under test with the ratio error ranges of $0{\sim}{\pm}10%$. The ratio error of the CT comparator under test theoretically obtained in this method are consistent with that measured for same CT comparator under test by using wide ratio error CT within an estimated expanded uncertainty (k = 2) in the overall ratio error ranges.

• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.2
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• pp.7-14
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• 1979

Design considerations of I2L are discussed with particular emphasis on the upward current gain of the npn transistor, 6J Several test structures have been fabricated to measure the DC and AC characteristics of the I2L basic cell and the base current components of the npn transistor. A T flip-flop has also been designed and fabricated using the I2L technology. The upward current gain of 10 the speed -power product of the 2.6pJ/gate and the minimum propagation delay time of 36 nsec have been obtained from the test structure. The maxmum toggle frequency of the T flip -flop has been measured to be 3.5 MHz.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.10
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• pp.683-693
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• 1988

For the economical and reasonable operation of electric power system according to continual increase of electric power demand and decrease of load factor, the potential application of superconducting magnertic energy storage [SMES] with high efficiency and fast response in the electric utility is receiving attractive attension. In the light of this background, to confirm the basic principle of SMES, theoretical study, design technique and fabrication procedure for superconducting coil, current lead, cryostat, measuring and protection system of SMES are described in detail. Especially, a new design technique for superconducting coil and current lead is porposed and it was proved experimentally by the performance test of SMES which is developed for the first time in our country. At the peak operating current 200A, the maximum magnetic field amd stored energy of the coil are 3.52T and 2500J, espectively. The thermal and mechanical stability of 2500J SMES is also confirmed experimetally by its characteristics test, AC loss, protection system, charge and discharge test. The experimetal results show good characteristics of energy storage system.