• Title/Summary/Keyword: Electric safety

Search Result 1,827, Processing Time 0.036 seconds

The Thermal Characteristics of Partially Disconnected Wire Happened in Plug (플러그 내부에서 발생된 소선 단선에 의한 발열특성)

  • Jee, Seung-Wook;Kim, Shi-Kuk;Lee, Chun-Ha
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.25 no.4
    • /
    • pp.104-110
    • /
    • 2011
  • There are over 30[%] of electric fires in Korea happened at wire or wiring devices. For its prevention many safety devices are set up electric equipments. These safety devices are not working in a rated current's condition of electric equipment. But when wire is partially disconnected, electric fire is able to be happened even though current is smaller than a rated current value. This paper studied thermal characteristics and fire ability when wire in plug is partially disconnected. The experiment is progressed a method that inner wire of plug is partially disconnected and after that current that is less than a rated current is flowed. As the result, heating occurred in near of partially disconnected wire makes that outer sheath is melted, plug cover is carbonized, and even sometimes wire is fused. And results of analysis of thermal image of partially disconnected wire happened in plug, it shows a difference to heating distribution and temperature appeared surface of plug depend on a progress of a partially disconnected wire.

A Study on Fire Investigation Technique For Single Line to Ground Faults in Distribution Line Using EMTP Simulation (EMTP 시뮬레이션을 통한 배전선로의 1선 지락 사고시 화재 조사 기법에 관한 연구)

  • Yoo, Jeong Hyun;Kim, Hie Sik;Lee, Hoon Gi;Cho, Yong Sun
    • Journal of the Korean Society of Safety
    • /
    • v.33 no.3
    • /
    • pp.21-26
    • /
    • 2018
  • Approximately 20% of the total fire is electrical fire, and electrical energy is a potential source of heat. Large-scale fault currents that occur during a line ground fault flow into electric utility poles, electric power equipment, or electric appliances of the customer, and cause simultaneous electrical fire. In this paper, we investigated the possibility of fire through the change of fault current flowing in faulty and sound feeder in case of 1 line ground fault in 22.9 kV distribution line. We propose a fire investigation analysis method for simultaneous multiple electrical fire such as evidence analysis method, and fault current occurrence confirmation method in case of fire accident by analyzing the fault current occurring in the ground fault in the distribution line using EMTP, electric power system analysis program.

The Study of the Harmonic Currents Effects on the Transformer Vibration (고조파 전류가 변압기 진동에 미치는 영향에 관한 연구)

  • Kim, Su-Yeol;Kim, Yeon-Whan;Kim, Jang-Mok;Lim, Ik-Hun;Lee, Hyun
    • Journal of the Korean Society of Safety
    • /
    • v.15 no.1
    • /
    • pp.106-111
    • /
    • 2000
  • EP(Electrostatic Precipitator) has been used to keep the natural environment from fly-ash in the industrial fields and operated in intermittent PEC(Pulse Energized Control) mode to improve dust-collecting efficiency. Intermittent PEC mode induces low-frequency harmonic currents into power system, therefore EP transformer vibrates. This continuous transformer vibration developes transformer abnormal audio-noise and if it is too much or operates in the region of natural frequency, transformer will be damaged in the end. EP interruption caused by transformer damage results in power generation stopped, power quality down and economic loss. Therefore, this paper explains harmonic currents and transformer vibration-core vibration, winding vibration, and proposes the measures of suppressing the vibration with EP operated in intermittent PEC mode. And this results is proposed to be used for future EP transformer design or EP control method to operate EP-concerned equipment safely keeping from system faults caused by transformer vibration.

  • PDF

Influence of Partial Discharge Properties due to Void in Cable Joint Parts (케이블 접속재 부분방전 특성에 미치는 보이드의 영향)

  • 신종열;홍진웅
    • Journal of the Korean Society of Safety
    • /
    • v.18 no.3
    • /
    • pp.69-74
    • /
    • 2003
  • To investigate the partial discharge and electric field distribution in cable joint parts, we measured the partial discharge and electric field in specimen. The specimens which cross-linked polyethylene(XLPE) and ethylene propylene diene ethylene(EPDM) are used to insulating material for underground cable md cable jointing parts. The polymers are used to insulating material in switchgear which is a kind of transformer equipment and in ultra-high voltage cable. Its using is increasing gradually, the electrical insulation properties are not only excellent but also mechanical property is excellent. And because it is possible to be made void of several type in insulator while it is produced, which the electrical field distribution is changed by void, it has a critical influence to insulator performance. The underground cable is connecting by the jointing material, insulating breakdown and the electric ageing which are caused by several mixing impurity and the damage of cable insulator layer, which reduced the life of cable while intermediate joint kit is connected. Therefore, the computer simulation is used to estimating insulator performance, XLPE is used to the insulating material of ultra-high voltage cable and EPDM is used to insulator layer in joint material kit, and which are produced as specimen. And it is analyzed the electric field concentrating distribution and partial discharge by modeling of computer simulation in void and cable joint kit.

A Statistical Analysis of External Force on Electric Pole due to Meteorological Conditions (기상현상에 의한 전주 외력의 통계적 분석)

  • Park, Chul Young;Shin, Chang Sun;Cho, Yong Yun;Kim, Young Hyun;Park, Jang Woo
    • KIPS Transactions on Computer and Communication Systems
    • /
    • v.6 no.11
    • /
    • pp.437-444
    • /
    • 2017
  • Electric Pole is a supporting beam used for power transmission/distribution which is sensitive to external force change of environmental factors. Therefore, power facilities have many difficulties in terms of maintenance/conservation from external environmental changes and natural disasters that cause a great economic impact. The aerial wire cause elasticity due to the influence of temperature, or factors such as wind speed and wind direction, that weakens the electric pole. The situation may lead to many safety risk in day-to-day life. But, the safety assessment of the pole is carried out at the design stage, and aftermath is not considered. For the safety and maintenance purposes, it is very important to analyze the influence of weather factors on external forces periodically. In this paper, we analyze the acceleration data of the sensor nodes installed in electric pole for maintenance/safety purpose and use Kalman filter as noise compensation method. Fast Fourier Transform (FFT) is performed to analyze the influence of each meteorological factor, along with the meteorological factors on frequency components. The result of the analysis shows that the temperature, humidity, solar radiation, hour of daylight, air pressure, wind direction and wind speed were influential factors. In this paper, the influences of meteorological factors on frequency components are different, and it is thought that it can be an important factor in achieving the purpose of safety and maintenance.