• Title/Summary/Keyword: Electrical accident

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Influence of Defects on Electrical Characteristics of Distributing Cable Termination (배전급 케이블 종단부의 결점이 전기적 특성에 미치는 영향)

  • Kim, Sang-Hyun;Choi, Jae-Hyeong;Choi, Jin-Wook;Kim, Young-Seok;Kim, Sun-Gu;Baek, Seung-Myeong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.2
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    • pp.190-195
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    • 2009
  • This paper introduces experimental investigates of an electrical accident of the distributing cable termination with simulated a shoddy construction. We prepared two termination kites, one is built-in type, the other is heat contraction type. Also, we manufactured cable termination that have simulated defect by badness construction and investigated their insulation characteristics such as ac (35[kV], 1[min]) and impulse (95[kV], $1.2{\times}50[{\mu}s]$) withstand test. The influence of defects such as thickness decrease, the gap between stress-con of housing and semiconductor and heating time on insulating properties of the termination have been studied. The thickness decrease of an insulator decreases ac breakdown strength suddenly and the breakdown traces of the insulator that is damaged by knife displayed elliptic shape. The gap of between stress-con and semiconductor deteriorates dielectric strength of insulator seriously. In heat contraction type, the ac breakdown voltage became low when the heating time is short.

A Study on the Development of Remote Diagnosis System for Nerve Conduction

  • Kim, Jong-Weon
    • Journal of Electrical Engineering and information Science
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    • v.3 no.3
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    • pp.286-291
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    • 1998
  • A remote measurement system for nerve conduction has been developed to aid patients with spinal cord injury by accident. Existing cooperation between rescuers and doctors can be supported through the introduction of multimedia desktop video conferencing. Such facilities provide several advantages over conventional video conferencing. In particular, patients may feel free because they can see a doctor through the video conferencing facilities. This paper describes the system implementation and evaluation. The author considers the network capability and image data handling, and introduces a method a transmit image data for this system.

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Study on the Damage Pattern Analysis of a 3 Phase 22.9/3.3kV Oil Immersed Transformer and Judgment of the Cause of Its Ignition (3상 22.9/3.3kV 유입변압기의 소손패턴 해석 및 발화원인 판정에 관한 연구)

  • Choi, Chung-Seog
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.6
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    • pp.1274-1279
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    • 2011
  • The purpose of this paper is to present the manufacturing defect and damage pattern of a 3 phase 22.9/3.3kV oil immersed transformer, as well as to present an objective basis for the prevention of a similar accident and to secure data for the settlement of PL related disputes. It was found that in order to prevent the occurrence of accidents to transformers, insulating oil analysis, thermal image measurement, and corona discharge diagnosis, etc., were performed by establishing relevant regulation. The result of analysis performed on the external appearance of a transformer to which an accident occurred, the internal insulation resistance and protection system, etc., showed that most of the analysis items were judged to be acceptable. However, it was found that the insulation characteristics between the primary winding and the enclosure, those between the ground and the secondary winding, and those between the primary and secondary windings were inappropriate due to an insulating oil leak caused by damage to the pressure relief valve. From the analysis of the acidity values measured over the past 5 years, it is thought that an increase in carbon dioxide (CO2) caused an increase in the temperature inside the transformer and the increase in the ethylene gas increased the possibility of ignition. Even though 17 years have passed since the transformer was installed, it was found that the system's design, manufacture, maintenance and management have been performed well and the insulating paper was in good condition, and that there was no trace of public access or vandalism. However, in the case of transformers to which accidents have occurred, a melted area between the upper and the intermediate bobbins of the W-phase secondary winding as well as between its intermediate and lower bobbins. It can be seen that a V-pattern was formed at the carbonized area of the transformer and that the depth of the carbonization is deeper at the upper side than the lower side. In addition, it was found that physical bending and deformation occurred inside the secondary winding due to non-uniform pressure while performing transformer winding work. Therefore, since it is obvious that the accident occurred due to a manufacturing defect (winding work defect), it is thought that the manufacturer of the transformer is responsible for the accident and that it is lawful for the manufacture to investigate and prove the concrete cause of the accident according to the Product Liability Law (PLL).

The Analysis of Field Condition for Emergency and Standby Power Systems in amusement park and ride (유원시설에서의 예비전원설비 현장실태 분석)

  • Kim, Chong-Min;Kim, Gi-Hyun;Yi, Geon-Ho;Bang, Sun-Bae;Kim, Han-Sang;Bae, Seok-Myung
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.11a
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    • pp.275-279
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    • 2004
  • Amusement park's indispensable facilities are dependent on electrical energy. So it is very important to ensure electrical power against fire, power failure, disaster and accident. To find out present problems, investigation was carried out for emergency and standby power systems at amusement park all over the country. We research the related regulations for Electrical facilities of internal standards and NEC. As a result, we could know that there is discrepancy between the electrical regulation and the actual condition.

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A Study on the Characteristic of Electrical Construction Work for Prevention of Electric Shock Accident (감전재해 예방을 위한 전기공사업의 특성에 관한 연구)

  • Choi, Sang-Won
    • Journal of the Korean Society of Safety
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    • v.29 no.5
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    • pp.29-34
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    • 2014
  • The live line working is inherently dangerous as the workers have to work under the risk of electrical shock and most of works are carried out at height. The live line working need the some specific techniques and higher level safety measures such as a risk assessment to carry out works safely, but the electrical construction companies performed live-line working are usually small-sized companies. They have less capacity to have own safety management system. This study intended to conduct an in-depth analysis on the cause of electric shock accidents to provide basic data for policy proposing taking into considering the past eleven years for a long-term plan. And the aim of this study is to propose the policy about the equipment performance standards and/or worker's safety standards to revise the standards for preventing electric shock accidents, moreover, co-relation of the electrical work order form and on safety workings, especially electrical construction company/work.

Study about the Design of Special Blade and Simulation for Wind Generation system (풍력발전 시스템의 특수 블레이드 설계 및 시뮬레이션에 관한 연구)

  • Yoon, Jeong-Phil;Lee, Gi-Je;Yoon, Hyung-Sang;Yoon, Seok-Am;Cha, In-Su
    • Proceedings of the KIEE Conference
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    • 2004.04a
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    • pp.192-195
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    • 2004
  • Into investment expense that wind generation system that is one of clean energy is less than existent energy in narrow shipfitter maximum effect to source of energy that have Eoteulsu evaluate. There is shortcoming that Blade structure of existent aerogenerator faces at problem of safety accident in overpopulated area and noise and have additional expense of supply of electric power equipment. In this paper, We wish to supplement problem that is such through design of special Blade structure that have noise reduction and stability. Wish to achieve design and simulation of blade to use CATIA for this, and analyze adaptedness of system.

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A Study on the Data Aquisition System for Power Quality Analysis of Load Equipment (부하설비의 전력품질 분석을 위한 데이터 획득시스템에 관한 연구)

  • Yu, Jae-Geun;Lee, Sang-Ik;Choe, Gyu-Ha
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.92-94
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    • 2007
  • In order to analyze voltage, current, electrical power, harmonics and so on of electrical load equipments, electrical power analysis by real measurement rather than mathematical modeling is necessary, and plan of countermeasure for efficient management, energy frugality and accident prevention of electrical equipments using it is possible. Especially, electrical power analysis by real measurement is indispensable in order to consider countermove of harmonic occurred by nonlinear load. So, in this paper, we developed DSP(Digital Signal Processor) based low price date aquisition system, and verified it's ability by performing measurement and analysis of electrical power and harmonic in the real power system.

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The Accident Hazard and Properties of the Leakage Current on the Electrical Insulation by Pollution (전기 절연물의 오염에 따른 누설전류 특성 및 사고위험성 연구)

  • Kim, Young-Seok;Shong, Kil-Mok;Jung, Jin-Su;Jung, Jong-Wook;Kim, Sun-Gu
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.05a
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    • pp.463-467
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    • 2007
  • It is necessary to study the prevention and the management of electrical facilities because the electrical fault took place at the dust occurrence area due to environmental pollution. In particular, the dust accumulates easily on insulation material which is exposed an external long time. The leakage current brings out electrical fault after all. Also, it is need to variation of material and shape to repress a leakage current on electrical material. In this paper, we measured a leakage current on electrical material of facilities by dust, and in experiments the prevention to electrical fault was studied.

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A STUDY ON THE AGING DEGRADATION OF ETHYLENE-PROPYLENE-DIENE MONOMER (EPDM) UNDER LOCA CONDITION

  • Seo, Yong-Dae;Lee, Hyun-Seon;Kim, Yong-Soo;Song, Chi-Sung
    • Nuclear Engineering and Technology
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    • v.43 no.3
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    • pp.279-286
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    • 2011
  • The aging degradation and lifetime assessment of a domestic class 1E Ethylene-Propylene-Diene-Monomer (EPDM), which is a popular insulating elastomer for electrical cables in the nuclear power plants, were studied for equipment qualification verification under the Loss of Coolant Accident (LOCA) conditions. The specimens were acceleratively aged, underwent a LOCA environment, as well as tested mechanically, thermo-gravimetrically, and spectroscopically according to the American Society of the Testing of Materials (ASTM) procedures. The tensile test results revealed that the elongation at break gradually decreased with an increasing aging temperature. The lifetime of EPDM aged isothermally at $140^{\circ}C$ was 1,316 hours and reduced to 1,120 hours after experiencing the severe accident test. The activation energies of the elongation reduction were $1.10{\pm}0.196$ eV and $0.93{\pm}0.191$ eV before and after the LOCA condition, respectively. The TGA test results also showed that the activation energy of the aging decomposition decreased from 1.35 eV to 1.02 eV after undergoing the LOCA environment. Although the mechanical property changes were discernibly observed during the aging process, along with the LOCA simulation, the FT-IR analysis showed that the spectroscopic peaks and their intensities did not alter significantly. Therefore, it can be concluded that the degradation of the domestic class 1E EPDM due to aging can be tolerable, even in severe accident conditions such as LOCA, and thus it qualifies as a suitable insulating material for electrical cables in the nuclear power plants.