• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.502-505
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• 2003

The accidnet of breaking insulator rod leads to inturruption of moving the subway. We investigate the analysis of analysis of breaking accident of FRP insulator rod installed in dead section for catenary feeding system. To analysis of accident reason, SEM is used to analysis microscopic struture on surface of cross section of broken FRP insulator rod. At the same time, we examine the chage of atomic amount on solace of accident insulator through EDX analysis. Also, the test for tensional breaking load is condoled to check the mechanical strength.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.4
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• pp.263-266
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• 2019

In the Airport Railroad, the Yeongjong Bridge has a length of 4,420 m and connects Yeongjong Island with the mainland of Incheon City. The bridge is a two-level structure, consisting of a six-lane road at the upper level and a combination of a road and railroad at the lower level. The environmental conditions for the electric railway come mainly from the salt injury area and a heavy industry zone, and the maintenance cycles are determined differently depending on these conditions. This study analyzed the deterioration characteristics of long rod insulators produced with a movable ceramic bracket and polymer materials in the Yeongjong Bridge section of the Airport Railway operating in the salt injury area according to the material characteristics. Comparison of the corona measurements when the insulators were cleaned at the same time showed that the polymer insulator had a higher insulation performance than the ceramic insulator.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.229-232
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• 1997

In this paper, we describe about the field test of polymeric long rod insulator for rail way. For the test, insulators were mounted at the feeder line system at Kuro base station and were exposed to environmental, electric, and mechanical stress. During the test service, the leakage current was been monitoring and stored the data by the leakage current measuring system that was specially constructed. After about 6 months, diagnostic tests for evaluation of the installed insulators were conducted. The test results developed that the developed polymeric insulator is valid to use for rail way.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.436-441
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• 1998

We developed the composite long rod insulator for railway, and the developed insulators were applied to commercial lines, KNR through a series of preparations such as establishment of specification, diverse tests and evaluation of reliability, and improvement of manufacturing system, etc. This paper presents some considerations for mass Production of the composite insulators in view of steady quality especially. 1 believe that our tries, though it is incomplete in view of low cost, is effective in good performance of the insulators in service and these in-service experience is enough to be a basis of more progress in field of insulation technique.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.228.2-228.2
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• 2016

The triggered vacuum switch (TVS) discharges high current through two processes. In the first process, an igniting plasma is generated at a trigger system, and the next process that a main discharge is taken place sequentially at a six-gap rod electrode within a few microsecond. In general, a triggered voltage producing the igniting plasma is increased. However, after several hundred shots, it goes down and stable, in our experiment the trigger voltage is about 5 kV after 250 shots. This triggered characteristics comes from the ceramic insulator which is covered by an electrode material, therefore we have focused on the first igniting plasma process. The igniting plasma has been generated at the surface of a ceramic insulator under a strong electric field. The electric field can be increased through modifying geometries of trigger components which compose of a trigger pin, a ceramic insulator and an enclosed holder. We fabricated not only two types of trigger pin which are a plane head and an umbrella head type, but two different holders which are a concave and a convex type. In this paper the result that the dependency of geometries for these four combined types is included, but the study of the ceramic insulator is not. The research of the ceramic insulator will be announced in the other paper.

• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.261-262
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• 2008

Damaged glass insulator that is utilized the high-speed railroad in domestic try to find the cause. This paper is investigated on the characteristics of alumina cement as the binder of class insulator. The components of glass insulator ore stub(tin), rod(tin), shed(tempered glass), and alumina cement. If composition of alumina cement is not unified, crack of alumina cement generated. As these results, cracked marks of cement is appeared and composition of alumina cement is not unified. Therefore, it is estimated that main element of long-term degradation is a alumina cement.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1796-1803
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• 2015

While considering the current scenario, in this world power demand goes on increases day by day. Frequent power outages occur in high voltage transmission line due to the deprived performance of polluted insulators; this affects overall operation of power system and may indirectly impinge on the growth of production sector. Many researchers are keenly taking efforts to provide highly reliable and stable power to neediest. In this paper, A.C pollution flashover performance of disc type glass insulator and composite long rod insulators investigation under various artificial pollutions by varying Equivalent Salt Density Deposition (ESDD) levels. Here, we use different types of pollution methods like binding method, dipping method and spraying methods with different types of pollutants concentration. Based on dimensional analysis, four different Mathematical models have been developed to predict the A.C pollution Flashover Voltage (FOV) of insulators. Both the experimental and mathematically modeled results are compared; it's observed that mathematical model 3 yields better results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.59-61
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• 2001

Polymeric suspended insulators for the electric track line have been developed. The main elements to design polymeric insulators are the insulation ability related with materials of FRP core and housing, and the optimal structure related with fitting parts and interface characteristics. To confirm the design fitness of insulator samples the electric field distribution by FEM and mechanical stress distribution by NASTRAN program was analysed with housing shed shapes and fitting structure. The leakage distance and breakage voltage properties which are core parameters to determine electric insulation ability are selected according to the requirement values of user specification, then the power frequency wet withstand voltage was specified above 22kV and the leakage distance was required above 290mm. The contamination condition of the electric track line was the heavy class according to IEC 815 in order to retain the enough safety margin against overvoltages.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1499-1501
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• 1994

This paper studies on the outdoor field test facilities which are established for weather-resist and mechanical-resist property teat of composite insulator. We have established measuring and data acquisition system for various test conditions -leakage current, temperature, humidity, wind direction, wind velocity and rainfall. The merry-go-round test and salt fog test have been studied in order to evaluate non tracking property of rubber material. Especially we have checked the relationship between hydrophobicity and outdoor exposure degree by contact angle measurement.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.4
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• pp.321-326
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• 1998

Electrical breakdown characteristics of liquid nitrogen($LN_2$) taking into consideration for application of high $T_c$ superconductor is very important. Also $LN_2$ will be used as both coolant and insulator in superconducting generator. In this paper, we investigated ac breakdown characteristics of cryogenic nitrogen gas above a $LN_2$ for rod-to plane electrode configuration. As result the breakdown mechanism of $LN_2$is dependence on bubble effect. And breakdown voltage is a ratio on bubble s size but electrodes arrangement is to make no difference. The breakdown voltage decreases slightly with increasing flow velocity, it again decreases abruptly with increasing flow velocity. These results were interpreted as the within pressure of rod electrode and Maxwell force.