• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1159-1162
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• 2003

Recently we suffered lot of failures of polymer surge arresters made by same manufacture after one year field operation. In order to set up countermeasures we investigated the causes of failures. We extracted faulted arresters and sound ones which were installed in same pole with faulted ones for the electrical test and dissection. 44 arresters were removed from 8 branch offices. Almost all of faulted arresters hadtracking damage on the interface between inner module and housing and the surface of inner module was very rough and irregular. It was possible to occur moisture ingress into the interface between inner module and housing due to the void of the interface and non tight sealing caps. Lots of sound arresters were failed during the moisture ingress test. This result must relate with tracking damage of faulted arresters. Therefore we can say that arresters had poor interface and sealing system. But we could not found aging and defects of ZnO elements because the electrical performance except moisture ingress test of arresters showed good.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.8
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• pp.691-696
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• 2007

In this study accelerated aging test equipment was developed to simulate domestic weather condition for accelerated aging test of polymer housed distribution surge arresters. Polymer arresters were aged for 3,000 hours by this test equipment and chemical and electrical characteristics analysis of surge arresters were conducted after aging test. In addition, performance assessment of outdoor installed arresters for 3 years was conducted to compare aging effect between accelerated aging test and natural aging. Through this experiment it is verified that the capability of the proposed aging test for simulating natural aging and the housing material and disconnector of domestic polymer arresters can be deteriorated by the long time field operation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.513-514
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• 2006

This paper presents the temperature characteristics with the structure of 18 kV surge arresters for distribution system. Three types of polymer arrester were fabricated and a ceramic arrester was also prepared to investigate. Below $100^{\circ}C$, three types of polymeric arresters exhibited almost the same leakage current value, but above $100^{\circ}C$, the polymeric arresters whose module was injected into polymeric housing with the grease exhibited the highest leakage current. In contrary, the arresters being manufactured by directly injecting silicone rubber onto arrester module exhibited the lowest leakage current. The rapid rising of leakage current of the polymeric arresters with the grease at $120^{\circ}C$ was because of the deterioration of the insulation characteristics of the grease between the FRP module and the silicone housing. All polymeric arresters exhibited the same surface temperature characteristics but the ceramic arresters was slower than the polymer arrester in heat emission despite the lowest leakage current. It was thought that the air layer between ZnO varistor blocks and the ceramic housing prevented the heat emission.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.210-213
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• 2007

In this study accelerated aging test cycle and equipment was developed for aging test of polymer housed surge arresters under domestic weather condition In order to investigate aging characteristics of polymer surge arresters electrical and chemical analysis of the arresters which are used for accelerated aging test and outdoor exposure test were conducted. Through the analysis the capability of the proposed method was verified and characteristics data were presented for maintenance of domestic arresters. Based on these results long term reliability assessment method was proposed for polymer housed distribution surge arresters.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.4
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• pp.269-277
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• 2002

Dynamic characteristics of water hammer arresters installed in a building water supply system have been investigated numerically by utilizing a commercial rode that employs the method of characteristics. Some preliminary results with those arresters produced in this study agree well with the previously reported. Then, the arresters have been incorporated into a water supply pipe system of a $59m^2$ apartment unit constructed by a leading construction company, and their dynamic characteristics, especially on the reduction in the water hammer pressure, are investigated. It is found that the setting of the arresters in the pipe system, which is recommended by the company, may not be proper for reducing the pressure to less than 1082.0 kPa when buick-closure valves in the pipe system are closed within 30 ms at the static pressure of 542.6 kPa. More arresters in the system may be required to meet a pressure criteria.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.2
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• pp.62-67
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• 2002

This paper provides the results of accelerated aging test of 18kV ZnO lightning arresters to investigate the leakage current characteristics. It was impossible to establish the replacement criterion for field operating lightning arrester because conventional aging test was only focused on the aging of ZnO elements. In general, it is possible to replace the aged arresters before the failure in the field using the leakage current measurement because it must be increased by the aging. But we can not use the method because we don't know the characteristics of the installed lightning arresters. Therefore in this paper we applied operating voltage and accelerating cycle which consists of temperature and humidity to the arresters. Then we measured the variation of total and resistive leakage current and found out the characteristics of the acted lightning arresters.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.3
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• pp.273-280
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• 2007

In this paper, the ZnO surge arrester performance of power distribution class has been studied under different manufacturing conditions such as housing materials(polymeric, porcelain), interface sealants and one-body molding type. In the recent years, the polymeric ZnO surge arresters have been developed and put into operations based on their excellent characteristics. For polymeric surge arresters, the inner gas volume is extremely small, especially in solid insulation polymeric arresters there are not any gas volume inside arresters in the structure due to polymeric materials are filled into the internal gas volume. The sealing integrity is related to safe operation of surge arrester, the prime failure reason of porcelain housed arresters is moisture ingress. In this paper, the sealing integrity of polymeric surge arresters is investigated with moisture multi-aging test and ingress test. The evaluation techniques are used to inspect the sealing integrity of polymeric arresters, including leakage current, surface temperature, reference voltage and dissipation factor.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1442_1442
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• 2009

This paper describes electric field analysis and design of direct current arresters for electric traction vehicles. Generally, DC arresters are used to protect the electric traction to limit the overvoltage invading into its inner electrical circuits. We could proposed operating voltage(Uc), the rated voltage(Ur). Finally maxwell 2D simulator based on the boundary element method was also introduced in order to verify the reliability of the DC arresters.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1642-1644
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• 1999

This paper provides the results of dielectric properties for aged or controlled lightening arresters. The aged lightening arresters were used for five years in distribution line. The leakage current of lightening arresters and elements was measured to confirm whether the lightening arrester was deteriorated or not. The microstructure was also investigated to determine the size of grain and grain boundary. The dielectric properties of aged lightening arresters were compared to those of controlled lightening arresters. The dielectric constant and the tan${\delta}$ of aged lightening arrester were larger than those of controlled one, resulting from accelerated aging due to the thin grain boundary.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.485-488
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• 2001

This paper provides the result of analysis of the structure and I-V characteristics of D.C. 1500 V surge arresters which were installed in railway line currently. As Porcelain housed surge arresters have unstable elements such as exploding and dispersion, so it is thought that the system is protected more stably with replacement of polymer housing. The adoption of gap mitigates the voltage stress which is degradation factor of surge arresters and the research is needed to enhance the life characteristic in additive and manufacturing process. Therefore, it is thought that the research should be continued to develop homemade the surge arresters for D.C. railway line as well as transmission line.