• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1754-1760
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• 2010

The HVDC system consists of ac side and dc side through thyristor valve. ac side protection is similar to conventional ac system protection schemes but dc side protection is different from ac side of HVDC system. AC system don't have controller but HVDC system has controller that controls and protects system from faults and disturbance. This paper show protectional function of HVDC dc side such as asymmetry protection, ac/dc differential protection, dc overvoltage, dc overcurrent protection. Protection models is developed using RTDS software and assessment of protection models is also performed by RTDS system.

• Journal of Astronomy and Space Sciences
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• v.1 no.1
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• pp.35-39
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• 1984

The design of the reusable thermal protection system for the space shuttle orbiter using silica tile played one of key roles in the successful flight of the Columbia and subsequent space shuttles. The basic design goals for this thermal protection system were identified. Manufacturing procedures for the silica tile and the structure of the tile system were also described.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.385-387
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• 2008

When a fault occurs in the distribution system, it is detected by protection system, then protection system is opened and de-energises the feeder where the fault exists. in this paper, the failure rate of protection system will estimate that using a discrete markov approach with failure data of protection system in order to improve the reliability of protection system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.9
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• pp.97-107
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• 2010

Penetration of distributed generator(DG) to power distribution system can cause malfunction of existing protection schemes. Because grid interconnected DG can contribute fault currents and make bidirectional current flows on the system, fault contributions from DG can cause an interference of protection relay operation. Therefore, over current protection device of the distribution system with DGs need directional protection schemes. In this paper, improved directional protection algorithms are proposed for the distribution system with DG considering their fault characteristics. And than, these directional protection algorithms are tested and validated in various fault conditions. From the simulation results, it can be seen that the proposed directional protection algorithms are practically efficient for the radial distribution system with DG.

• Fire Science and Engineering
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• v.23 no.2
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• pp.55-61
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• 2009

This study has been carried on the transient phenomenon protection system to become fire alarm system control unit of high reliance which can be protected from transient phenomena for surge or transient overvoltage, and constructed engineering base that can develop transient phenomenon protection system by proving performance of protection system in a experimental. This study developed 1 step and 2 step protection system that can be protected from transient phenomenon with process thesis and theory for development of transient phenomenon protection system. It established engineering data construction and a source technology that can develop transient phenomenon protection system as gets satisfied result and test with all performance condition that present in fire protection law and connection regulation.

• Fire Science and Engineering
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• v.33 no.3
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• pp.98-104
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• 2019

This study examined the efficient management of a fire protection system using spatial information, and basic data for the development of related firefighting industry were obtained. To overcome the problems of malfunction and management failure, which are the major issues of fire protection system management, this study analyzed the related laws and regulations on building spatial information of a fire protection system to introduce spatial information to the fire protection system field. For efficient management of the fire protection system, it is necessary to revise the related laws of the fire protection system, such as protection system-related laws including space information technology, and maintain the standardization, effectiveness, and consistency of fire protection system spatial information.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.36-42
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• 2011

This paper mainly proposes the protective coordination scheme of the microgrid system. The microgrid protection is identical to the conventional protection system separating the normal part and contingency part to reduce damage when the contingency occur at power cables, facilities. But they are different in the protection type. The conventional protection system only considers unidirectional current. However the microgrid protection should be considered not only unidirectional current but also backfeed current because various microsources and loads are installed in the microgrid system. In case the contingency occurs in microsource, when microgrid is interconnected to grid, the protection system should be configured to not separate microgrid from grid before the microsource is isolated to microgrid. And in case of fault occur in power system, the microsources should not isolated to microgrid before the static switch at PCC is tripped to separate from power system. Considering these characteristic of microgird, this paper proposes the protective coordination scheme of microgrid and implemented the on-line real time monitoring system. Especially in case the microgrid is connected to low voltage distribution system with 220/380V voltage level, the proposed protection method with power IT technology can solve the problems when the existing protective devices only applied to the microgrid system.

• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.480-485
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• 2012

Use of photovoltaic (PV) power generation system will become more widespread in the future due to anticipated cost reduction in PV technology. As the capacity of PV systems increases, a variation of power system frequency may prevent the stable output of PV system. However, the standard for the frequency protection of distributed generation in Korea Electric Power Corporation (KEPCO)'s rule does not include the setting of frequency protection. Therefore, this paper analyzes the correlation between the frequency protection requirements and the stability of grid-connected PV system for the adjustable operating setting of frequency protection. The distribution system interconnected with 3 MW PV system is modeled by Matlab/Simulink. The various values of frequency are simulated. For studied cases, the stability of PV system is analyzed. It is concluded that the setting of frequency protection is necessary to consider the stability of PV system.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.85-86
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• 2013

This paper describes the physical configuration and features of the advanced control and protection devices, and operation control and monitoring system that are connected to a real time simulator for LS Industrial System 80kV 60 MW Jeju HVDC Pilot Project. Highlight of simulation result are provided to demonstrate the control and protection functionality.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.3
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• pp.133-138
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• 2013

A large generator is an important role in transferring an electric power to power system. The IEDs of large generator often use microprocessor technology to obtain a digital relay system with a wide range of measuring, protection, control, monitoring, and communication functions. However, all generator protection and control systems in Korea imported from abroad and are being operated. In order to reduce the large expense and improve the reliable operation, development of generator protection and control system by domestic technology is required. This paper deals with the design of the IED of generator protection panel for development of generator protection and control system. The major emphasis of the paper will be on the description of hardware and signal processing test results and measurement accuracy of the prototype IED. By developing of generator IED based on DSP and microprocessor, replacement of the generator protection panel imports are expected to be effective.