• Journal of the Korean Solar Energy Society
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• v.25 no.4
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• pp.21-27
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• 2005

This paper summarizes the results of these efforts by offering a photovoltaic system structure in 50kW middle scale applications installed in Cho-sun University dormitory roof. The combination of photovoltaic system components are interconnected and system monitoring system will be summarized for the purpose of the increasing safety in this article. This paper describes configuration of utility interactive photovoltaic system which generated electric power supplies to dormitory. In order to installing the middle or large scale photovoltaic system, It must investigated the optimal design of system, compute quantity of power generation, economic rate of return and so on. In this paper represent 50kW utility photovoltaic system examination and developed simulation results. The performance of photovoltaic system has been evaluated and analyzed with simulation. The results obtained in this research will be much useful to prior investigation for installing utility interactive photovoltaic system.

• International Journal of Advanced Culture Technology
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• v.8 no.2
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• pp.58-67
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• 2020

In this paper, the maintenance training manual of EV vehicle was produced by utilizing digital twin technology and various sensors such as IR-based light house tracking and head tracker. In addition, through digital twin technology and VR to provide high immersiveness to users, sensory content creation technology was secured through animation and effect realization suitable for EV vehicle maintenance situation. EV vehicle maintenance training manual is 3D engine programming and real-time creation of 3D objects and minimization of screen obstacles and selection of specific menus in virtual space in the form of training simulation. In addition, automatic output from the Head Mount Display (HUD), EV vehicle maintenance and inspection, etc., user can easily operate content was produced. This technology development can enhance immersion to users through implementation of detailed scenarios for maintenance / inspection of EV vehicles" and 3D parts display by procedure, realization of animations and effects for maintenance situations. Through this study, familiarity with improving the quality of education and safety accidents and correct maintenance process and the experienced person was very helpful in learning how to use equipment naturally and how to maintain EV vehicles.

• Journal of the Korean Solar Energy Society
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• v.35 no.2
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• pp.11-19
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• 2015

Islanding is a phenomenon that EPS(Electric Power System) is continuously energized by PV PCS(Photovoltaic Power Conditioning System) even when EPS is isolated from the grid. Unintentional islanding will result in safety hazard, power quality degradation and many other issues. So, islanding protection of grid-connected PV PCS is a key function for standards compliance. Nowadays, many anti-islanding schemes are researched. But existing anti-islanding schemes used in PV PCS have power quality degradation and non-detection zone issues. This paper analyses not only detection performance of existed anti-islanding schemes using active frequency drift but also THD of PCS output current according to each value disturbance for anti-islanding. In addition, the lowest value of disturbance in each scheme was tabulated under guarantee of anti-islanding condition.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.755-770
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• 2006

1974. 8.15 SeoulMetro, beginning with the first electric railway established at six cities, so it is managing mass transportation of traffic. Especially, in case of seoul, It is managing that from one to eight lines, 286.9km, 265 stations have installed and now it is carrying about 5.5million of passengers everyday, and 2,000million passengers a year. So accident is increasing from the station every year. For this measure, SeoulMetro prepares safety fence for passengers crash but, as suicides or people who watch the accident took place, for at the bottom of passengers crash protection, PSD installing is needed. Even though, PSD is managing ATO section but, in controlling SeoulMetro, one to four lines sections are (ATS, ATC)section. Between as ATS, ATC section, ATO section, subway gate and PSD must have opened and crossed always at the time. And the interlock control corrosion protection gate, managing skills with installation, method, using in history, apply to 10rail cars one train sets, and maximum applying 224% sections of passengers congested that consideration is to be needed. So 2004, SeoulMetro improved technology and basic design of PSD at ATS section. Based on this, from 2005.4 to 2006.6, using subway 2lines per 12stations set the model installation(full type 11stations, half type 1station) After installing in case of success, it is going about to suggest that effective analysis and hereafter subject.

• Journal of the Korean Institute of Gas
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• v.8 no.4 s.25
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• pp.15-22
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• 2004

This study has been carried out to improve the conditions of process operation through the adjustment to the flow rate and outlet pressure of LNG HP pump, one of the main process facilities, in LNG receiving terminal. We have determined optimum flow rate and applied it to the field operation by analyzing the field operating performance for all the HP pumps and the load of natural gas supply in seasonal using the ASPEN PLUS. As a results, we have get the electric cost saving for the HP pump operation and derived contribution to safety operation by reduced the LNG Process pressure.

• Proceedings of the KIEE Conference
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• 2008.11b
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• pp.157-159
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• 2008

This paper summarizes the results of these efforts by offering a photovoltaic system structure in 50kW. The combination of photovoltaic system components are interconnected and system monitoring system will be summarized for the purpose of the increasing safety in this article. This paper describes configuration of utility interactive photovoltaic system which generated electric power supplies to dormitory. In order to installing the middle or large scale photovoltaic system, It must investigated the optimal design of system, compute quantity of power generation, economic rate of return and so on. In this paper represent 50kW utility photovoltaic system examination, developed simulation results and financial analysis. The performance of photovoltaic system has been evaluated, analyzed with simulation and financial analysis results. The results obtained in this research will be much useful to prior investigation for installing utility interactive photovoltaic system.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.1
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• pp.15-21
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• 2008

This paper presented a actual conditions on a false-tripping of ELB(Earth Leakage Breakers) and an assessment of the harmonics due to non-linear electronic equipment such as personal computers, rectifier, electric furnace and test equipments in factory electrical installation. Actual conditions on a failure of ELB were surveyed and analyzed by making up a question to safety managers of factory electrical installation. Also, power quality measurements such as harmonic currents, voltage and current waveform and current imbalance were made at various factory electrical installation where nuisance tripping of ELB is often occurred. The results of this study can be used in making decisions regarding cause of ELB trip and operating and tripping characteristics test of ELB when subjected to distorted current waveform.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1719-1720
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• 2006

High temperature superconducting(HTS) power cable is expected to be used for power transmission lines supplying electric power for densely populated cities in the near future. Commercializing of HTS power cable is coming. Simulation is required for safety before install of HTS power cable, 3 fabrication model used at the power system simulation. In this paper, we shows a single line-to ground fault analysis in the grid system which has a loom length HTS power cable. The authors developed a single line-to-ground fault current calculation method which is considering the shield layer of HTS power cable. In the calculation, the T type equivalent circuit is used to derive the mutual inductance of the HTS power cable.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.6
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• pp.427-432
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• 2018

High-capacity secondary batteries can cause explosion hazards owing to microcurrent variations or current surges that occur in short circuits. Consequently, complete safety cannot be achieved with general protection that is limited to a mere current fuse. Hence, in the case of secondary batteries, it is necessary for the protector to limit the inrush current in a short circuit, and to detect the current during microcurrent variations. To serve this purpose, a fuse can be employed for the secondary battery protection circuit with current detection. This study aims at designing a protection device that can stably operate in the hazardous circumstances associated with high-capacity secondary batteries. To achieve the said objective, a detecting fuse was designed from an alloy of low melting point elements for securing stability in abnormal current states. Experimental results show that the operating I-T and V-T characteristic constraints can be satisfied by employing the proposed current detecting self-contained low melting point fuse, and through the resistance of the heating resistor. These results thus verify that the proposed protection device can prevent the hazards of short circuit current surges and microcurrent variations of secondary batteries.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1679-1685
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• 2015

This paper examines the effect of the magnetization pattern on the partial demagnetization of a permanent magnet (PM) machine that uses a ferrite magnet. Although the use of halbach-magnetized PM (HMPM) arrays in PM machines has been dramatically increasing because of their attractive features, the demagnetization characteristics of HMPM arrays have not yet been examined. In this study, two analyses of the demagnetization characteristics of HMPM arrays and parallel magnetized PMs (PMPMs) are performed, with the demagnetization characteristics being analyzed using a finite element method. According to our results, partial demagnetization occurred dramatically in the HMPM arrays. Thus, it is important to consider the vulnerability of HMPM arrays when designing PM machines.