• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.05b
• /
• pp.76-81
• /
• 2004

This paper presents the results of spectral analysis of leakage current waveforms on contaminated insulators under various fog and environment conditions(salt fog, clean fog, rain) The larger the leakage current during 200ms, the higer the power spectrum at 60Hz. For almost equal maximum current during 200ms, however, the spectrum at 60hz and the odd order harmonics increase emphatically when discharges occur continuously for several half-waves. If contaminated insulators suffers from high salt-density fog, the leakage current occurs with high crest value intermittently, results in the low spectrum. Analysis of leakage current data showed that this electrical activity was characterized by transient arcing behavior contaminants are deposited on the insulator surface during salt fog tests. This provides a path for the leakage current to flow along the surface of the insulator. It is important to have an indication of the pollution accumulation in order to evulate the test performance of a particular insulator. If the drop in surface resistivity is severe enough, then the leakage current may escalate into s service interrupting flashover that degrade power quality.

• 전기산업
• /
• v.15 no.8
• /
• pp.73-80
• /
• 2004

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.935-938
• /
• 2002

The degree of contamination in outdoor insulation system is one of the most importance factor to determine the level of insulation, and the salt is known as the most dangerous contaminants in the most region of the world. In a macroscopic point of view, as shown through the preceding study, the generation and deposition of salt contaminants has a great relation with the geographical conditions and the meteorological conditions, such as, wind velocity, wind direction, precipitation and so forth. However, in the aspect of microscopic analysis, the pollution mechanism has a great relation with aerodynamic properties of insulator, originated from the profile of insulators, and the non-uniform deposition is unevitable. So, in this investigation, we had make a experiment to seize the electrical properties of non-uniformly contaminated insulator. The results of this investigation could be used as a good groundwork in the determination of outdoor insulation design.

• The Journal of Information Technology
• /
• v.7 no.2
• /
• pp.69-76
• /
• 2004

This paper presents the results of spectral analysis about waveforms and leakage current waveforms on contaminated silicon insulators under various environment conditions.(salt fog, clean fog, rain). The larger the leakage current during 200ms, the higher the power spectrum at 60Hz. If contaminated insulators suffers from high salt density fog, the leakage current occurs with high crest value intermittently, results in the low spectrum. Analysis of leakage current data showed that this electrical activity was characterized by transient arcing behavior contaminants are deposited on the insulator surface during salt fog tests. This provides a path for the leakage current to flow along the surface of the insulator. It is important to have an indication of the pollution accumulation in order to evaluate the test performance of a particular insulator. If the drop in surface resistivity is severe enough, then the leakage current may escalate into service interrupting flashover that degrade power quality.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1359-1360
• /
• 2007

In this paper, it is described the characteristics comparison of LV insulated materials contaminated by the salt vaporization and the particulates. The contact angle of normal PVC is measured $75^{\circ}$ but its of PVC contaminated by the salt vaporization for 500 hours is measured $63^{\circ}$. The contact angle of normal bakelite is measured $66^{\circ}$ but its of bakelite contaminated by the salt vaporization for 500 hours is measured $44^{\circ}$. And the contact angle of normal acrylic resin is measured $65^{\circ}$ but its of acrylic resin contaminated by the salt vaporization for 500 hours is measured $60^{\circ}$. In the surface of insulated materials contaminated by the particulate, the contact angle is decreased. The surface of bakelite is not good as an insulator.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1490-1491
• /
• 2007

The salt contamination on the distribution facilities, such as suspension insulator, line post insulator, lightning arrester, COS, is one of the major coastal areas because more than 90% of salt contaminated failure occurs in distribution facilities. Did to stain distribution facilities artificially according to Equivalent Salt Deposit Density(ESDD) grade. The electrical test were performed on the non-polluted and polluted facilities(ESDD B, C, D grade).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.11a
• /
• pp.36-41
• /
• 2003

This paper presents the results of power spectra using the fundamental and low frequency harmonic components of leakage current waveform to study aging on contaminated EPDM insulator(was serviced during 1997-2001, region Pohang, korea) under salt fog conditions. Experiments have been conducted in the chamber salt fog and at the 16KVrms. The salt contents adjusted as 0g,25g,50g and 75g per liter of deionized water. The onset of dry-band arcing on polymer insulators could be determined by signal processing the low frequency harmonics components. A correlation has been found between the fundamental and low harmonic components of power spectra on leakage current. Where aging could be associated with an increase in the level of both the fundamental and low frequency harmonics components of leakage current. Surface aging for contaminated EPDM insulators occurred when the fundamental component of leakage current was greater then some level On the other hand, when the polymer insulator approached failure, the fundamental component of leakage current reached relatively high values and low frequency harmonics components of the leakage current trended to decrease. The results suggest that both the fundamental and low frequency harmonics of leakage current can be used as a tool to determine both the beginning of aging and before flashover, end of life EPBM insulator in salt fog.

• Proceedings of the KIEE Conference
• /
• 1999.07e
• /
• pp.2083-2085
• /
• 1999

The same sized arcing horns have been installed on 345 kV transmission lines. Then arcing horn gaps are different according to the insulator string set. We need to examine the problems about the gap differences. So, we investigated the installation status of acing horn in 345 kV T/L. Based on these results. Drawing and making of the arcing horns for the contaminated areas is studied.

• Elastomers and Composites
• /
• v.34 no.5
• /
• pp.407-413
• /
• 1999

Non-ceramic composite insulator has been interested in the power industry because of its good characteristics in mechanical properties, mass product and design availability. Also it is lighter, and less unexplosive, compared to a ceramic insulator. Especially EPDM rubber composite insulator can be used for long-term in contaminated environments because of its hydrophobicity. This paper showed the rheological properties, the electrical properties, and contact angles to check the hydrophobicity and the recoverability of the EPDM compounds. Also, we investigated surface morphology of the compound by SEM.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.49 no.8
• /
• pp.390-398
• /
• 2000

Leakage impulse current of the contaminated insulators by using experiment data were studied. The impulse current in phase-time relationship was analyzed on line post insulators. Also, frequency components and crest factor of the leakage current were investigated to provide a scheme for an early detection of insulator incipient failure. The study shows that the phase-time characteristic is non-stationary and random and, non-harmonic component and crest factor can be promising parameters for detecting insulator leakage currents.