• Korean Journal of Materials Research
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• v.29 no.3
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• pp.137-142
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• 2019

The microstructure, phase, and mechanical properties of three aged porcelain insulators which were manufactured in different years (1973, 1995 and 2008) and which were used in the field for different amounts of time, were investigated. With X-ray 3D computed tomography (CT), defects with ~mm size can be detected without destroying the aged insulators. Defects of small specimens, which are cut from the aged insulators and polished, are analyzed with optical and scanning electron microscopy (OM and SEM), and defects of um size are detected by OM and SEM. The number and size of defects in all the aged insulators are similar. Porcelain insulators manufactured in 1973 contain more $SiO_2$ (quartz and cristobalite) than those manufactured in 2008. Those manufactured in 2008 contain more $Al_2O_3$ than those manufactured earlier. The Vickers hardness of the insulator manufactured in 1973 has the lowest value. The formation of the cristobalite ($SiO_2$) in the insulator manufactured in 1973 which can come from the phase transformation of quartz can cause stress in the insulator by formation of microcracks, which can lead to the low hardness of the insulator.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.2
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• pp.122-128
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• 2019

Porcelain insulators have been used mainly for power line fixing and electrical insulation in transmission towers. Porcelain insulators have generally a 30 years desired life, but over 50% exceed their life expectancy. Since the damage to porcelain insulators is usually accompanied by enormous loss of human resource material, their efficient maintenance has emerged as an important issue. In this regard, this study applied a frequency response function (FRF) for integrity assessment of the insulator. The characteristics of the FRF according to damage types were identified and analyzed by the change in natural frequencies, curve shape, attenuation, and Nyquist diagram stability. The results showed significant differences in the FRF according to damage types, which can be used as basic data for the effective integrity assessment of porcelain insulators.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1226-1228
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• 1995

This paper introduced foreign standard testing methods on composite insulators(for transmission, distribution) and mentioned on (1)evaluation of material property (2)short-term test of prototype (3)insulation efficiency on use to evaluation property of insulators made of composite insulating materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.152-152
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• 2009

Direct Current Fiber Reinforced Plastic (DC FRP) insulators were developed and their mechanical and electrical characteristics were investigated. Electrical tests were carried out to measure withstanding and flashover voltages under common use frequency condition. Tensile and bending tests were performed for the mechanical characteristics. The test results showed that DC FRP insulators had superior voltage resistances and strengths to porcelain insulators.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1912-1917
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• 2010

Fiber Reinforced Plastic (FRP) insulators for direct current (DC) were developed and their electrical characteristics were investigated. Electrical tests were carried out to measure withstanding and flashover voltages under common use frequency condition. Tensile and bending tests were performed for the mechanical characteristics. The test results showed that DC FRP insulators had superior voltage resistances and strengths to porcelain insulators.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1842-1847
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• 2000

In this paper, a review is attempted for understanding of aeolian noise from high voltage insulators and their aerodynamic noise characteristics were investigated using the low noise wind tunnel. The noise from the insulators was dependent upon the wind speed and their orientation relative to the wind direction. The noise spectrum revealed sharp peak which was found the cavity resonance frequency.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.553-555
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• 2000

Recently polymer insulators are being used for outdoor high voltage applications. Polymer insulators for transmission line have significant advantages over porcelain and glass insulators, especially for ultra-high voltage(UHV) transmission lines. In this paper, the design trend and method polymer insulator are investigated and Aging test method is analysed to know life time of insulator.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.66-68
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• 2001

Recently polymer insulators are being used for outdoor high voltage applications. Polymer insulators for transmission and distribution line have significant advantages over porcelain and glass insulators, especially for ultra-high voltage(UHV) transmission lines. Their advantages are light weight, vandalism resistance and hydrophobicity. In this paper, distribution polymer suspension insulator has been designed and investigated electric field distribution by FEM.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1743-1745
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• 1998

Insulators of 154kV T/L have been frequently damaged by fault currents. Arcing horn is a very effective and economic method for protection of insulators from the flashover. We developed arcing horns for 154kV T/L in order to protect insulators from the arc[1]. This paper analyzes the status of insulator failures in 154kV T/L after installation of the arcing horns.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.477-482
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• 2004

New materials are being considered for insulator of railroad vehicles. Because people want more environmental material than glass fiber, there are certain needs of finding safe and economical insulating material. We checked the flammability of some kinds insulators such as PE foam, neoprene rubber foam. melamine foam and glass fiber. You could find out the characteristics such as oxygen index. optical smoke density, toxicity index of that insulators.