• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1838-1841
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• 2004

This test was performed to assess the correlation between insulation diagnostic tests and breakdown voltage strength of the stator winding of 6.6kV class induction motor in insulation deterioration condition which have been in service for 5 years after being installed in 1998. The insulation diagnostic tests include resistance, polarization index(P.I), dissipation factor(${\triangle}tan{\delta}$), maximum partial discharges(Qmax) and AC breakdown test. we evaluated the correlation between insulation diagnostic test and AC breakdown test for stator winding of high voltage induction motor.

• Proceedings of the KIEE Conference
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• 2004.11d
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• pp.46-49
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• 2004

This test was performed to assess the correlation between insulation diagnostic tests and breakdown voltage strength of the stator winding of 6.6kV class induction motor in insulation deterioration condition which have been in service for 5 years after being installed in 1998. The insulation diagnostic tests include resistance, polarization index(P.I), dissipation factor(${\Delta}tan{\delta}$). maximum partial discharges(Qmax) and AC breakdown test. we evaluated the correlation between insulation diagnostic test and AC breakdown test for stator winding of high voltage induction motor.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.900-907
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• 2008

All electric trains in the city should be run without any troubles of the equipments in order to offer good services to the passengers. But some breakdowns occur when they are operated due to the long time uses. There are mechanical troubles and electrical troubles included reactors. Most of them, the reason of the troubles can be found out easily after breakdown. But it is difficult to find out the reasons of the reactor troubles which disappear after operation. The reactors of the train filter the current which supplied from electrical lines and supply the current to the inverter and block the ripple of the current. Partial discharge occur from the reactor by the heat. accordingly, If the signals of discharge were perceived, it could be anticipate the deterioration degree of insulation. In this paper, on-monitoring system for reactor's troubles in trains is established and the output results of monitoring system are investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.234-235
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• 2006

In this study, we experimented deterioration characteristics of PVC insulation wires for electrical apparatus by series arcing and analyzed the heat generation at the contacts of wires, glowing/growing process of copper oxide, waveforms of contact voltage, current, power dissipation, and so on. We found out that how glowing contacts and surface arcing can decompose PVC insulation and that subsequent series arc can lead to ignition. We expect that these results are useful for improving fire protection technology by providing a better understanding of how electrical fires can initiate.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1865-1867
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• 2002

In this paper, frequency spectra of AE signals detected from respective the insulation deterioration were analysed to under ac high-voltage application using epoxy resin sample and insulation oil. Also, frequency spectra of AE signals generated from the load currents in the actual operating transformer of 500[kVA] under distribution system of 22.9[kVJ] were also analysed to distinguish the AE signals due to void discharges from the magnetic circuit noises in transformer. As the experimental results, we could distinguish the AE signals whether those signals were caused due to the void discharges or due to the magnetic circuit noises by analyzing the frequency spectrum of AE signals.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.159-163
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• 2007

We studied the example of various side on effect the aging of exterior materials for concrete structure by analyzing the reason of water leakage in exist serviced skyscraper apartment. For this side, we would like to suggest the proper waterproofing materials and construction methods resulted in the mechanical performance test. So, it could be ensured the leakage safety for using residence facility and crowd utilization after repairing. It may maximize the durability for the concrete structure.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.636-639
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• 1993

This paper is discribed the results of insulation characteristic tests that are DC leakage current, test, tan${\delta}$ test, AC breakdown test and observation of tree in the used 6.6kV CV cables. In the correlation of these tests, the tan${\delta}$ test stands for the main deterioration factor of cable insulation.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.495-496
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• 2009

The restorative materials for deteriorated concrete are estimated by various kinds of strength, carbonation, and at same time, by various deteriorate factors and others. So, it's properties must have maintained many functional properties. In this study, to improvement of durability of restorative materials, we take restorative materials with insulation performance, for deterioration by temperature exchange as deterioration factor.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.10
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• pp.807-811
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• 2011

When the high voltage motor fails in power plants, there will be an occurrence where the generator's output would be reduced or the generators would trip. Despite of these effects, the causes of deterioration of the high voltage motor is very seldom investigated. In this paper, the collected data which tested in the field over 10 years have been treated statistically, and analyzed to correlate the insulation deterioration of high voltage motor and installation environment, number of start/stop, and service life. Moreover, the proper period of insulation test is developed to map out maintenance strategy and reduce maintenance costs.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.1-8
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• 2022

This study analyzed the characteristics of insulation resistance and operating time based on an accelerated degradation test of a low-voltage circuit breaker. The experimental sample used a molded case circuit breaker (MCCB) and an earth leakage circuit breaker (ELCB). After measuring the insulation resistance of the circuit breakers, the leakage current was affected by an external rather than an internal structure. Furthermore, the insulation resistance of the circuit breakers with accelerated degradation was measured using a Megger insulation tester. In the accelerated degradation test, aging times of five, ten, 15, and 20 years were applied according to a temperature derived using the Arrhenius equation. Circuit breakers with an equivalent life of ten, 15, and 20 years had increased insulation resistance compared to those with less degradation time. In particular, the circuit breaker with an equivalent life of ten years had the highest insulation resistance. Component analysis of the circuit breaker manufactured through an accelerated degradation test confirmed that the timing of the increase in insulation resistance and the time of additive loss were the same. Finally, after analyzing the operating time of the circuit breakers with degradation, it was confirmed that the MCCB did not change, but the ELCB breaker failed.