• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.4
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• pp.197-203
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• 2001

Recently, the construction of gas insulated substation(GIS)s has been increased in Korea. But, the whole quantity of the VTs which were used in GIS has been imported. Under the circumstance that $SF_6$ gas power apparatus are being developed up to 800kV rating in Korea, the development of EＨＶ　$SF_6$ gas VT is essential for localizing the power apparatus. As for EHV VT, destructive ferroresonance can be generated due to the combination of capacitiances between poles of circuit breaker, ground capacitance of bus and nonlinear excitation property of VT core. But the theoretical analysis about ferroresonance has not been fully achieved in Korea. Therefore, in this paper the authors would like to contribute for localizing EHV $SF_6$ gas VT by developing the diagram of ferroresonance zone according to the parameters of the circuit and the saturable reactor.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.5
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• pp.233-240
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• 1999

The current carrying conductor and the tank which consist of GIS must be properly designed to withstand the electrical, thermal and mechanical stresses that arise during normal service and during short-circuit conditions. In order to design the current carrying conductor for EHV GIS, it is important to consider temperature-rise when rated current flows. In this paper, we analyze magnetic field distribution and power-loss, according to the change of materials when AC current flows into single-phase and three-phase bus bar, respectively. These results will be used as the basic design data when determining dimensions and materials for the current carrying conductor of EHV GIS.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.541-543
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• 2002

This paper describes the analysis resulates on the P.T ferroresonance at 154kV GIS(Gas Insulated Substation) by EMTP(Electromagnetic transient program). We had simulated the PT ferroresonance between a potential transformer(PT) and open circuit braker's grading capacitance. The ferroresonance leads to very large power frequency overvoltage on PT bus and subsequent insulation failure. The damping circuit connected on the secondary winding were considered in the model. The actual countermeasure include a saturable inductor and a resistor series mounted, but the 2 ohms of damping resistance was used in the computational model.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2076-2079
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• 1999

This paper describes the analysis results on the PT ferroresonance at 154 kV GIS (gas Insulated substation by EMTP (Electro-magnetic Transient Program). We had simulated the PT ferroresonance between a potential transformer(PT) and an open circuit breaker's grading capacitance. The ferroresonance leads to very large power frequency overvoltages on PT bus and subsequent insulation failure. The large power can be supplied to the PT by the high voltage on the opened circuit due to the grading capacitance and equivalent capacitance of the buses during the ferroresonance. The damping circuit connected on the secondary winding were considered in the model. The actual countermeasure include a saturable inductor and a resistor series-mounted, but the 2 ohms of damping resistance was used in the computational model.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.5
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• pp.313-319
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• 2000

In order to design the current carrying conductor for GIS, it is important to predict temperature-rise when rated current flows in the bus bar. However, it is not easy to apply the correct heat transfer coefficient on the boundary between different material for the thermal analysis. In this paper, the heat transfer coefficient which depends on parameters such like material constant, model geometry as well as ambient temperature, was calculated by analytic method. The calculated coefficient is used for the temperature rise prediction by F.E.M. The results show good agreement with experimental data.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.507-512
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• 2017

Recently, more electric power facilities have been miniaturized and it is noted that the facilities maintenance will be essential through operation optimization. In this paper we applied and examined the operation optimization of electric power facilities by applying Matrix system which can improve reliability to minimize outage and recover failure rapidly when blackouts happen at 25.8kV Gas Insulated Switchgear(GIS). The fundamental problem for facilities maintenance of GIS can happen due to indeterminable internal state in real time. Matrix optimization organizes action states in all containers which contain pressurized $SF_6$ Gas such as circuit breaker, disconnector switch, bus for utilizing them each area. Then, we connect it with power system to monitor and control internal state remotely in real time, and we can minimize blackout zone or outage. Considering above process, we improved stability of overall facilities.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.482-484
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• 1995

In designing three phase enclosure type EHV class gas insulated bus (GIB), it is essential to estimate the magnitude and the position where the maximum electric field strength occur. The improvement of insulation design can only be initiated after those informations have been obtained. In this paper, the calculated electric field strength for three phase GIB of HICO 362kV 63kA GIS is presented. The result shows that the designed insulator has enough margin compared with the design criteria.