• Title/Summary/Keyword: Overload prevention

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Development of Prevention Apparatus for Short-Circuit Faults Using the Line Voltage Drop of Neutral Wire (중성선 선로 전압강하를 이용한 단락사고 방지용 보호장치 개발)

  • Kwak, Dong-Kurl;Kim, Jin-Hwan;Lee, Bong-Seob
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.12
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    • pp.1953-1958
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    • 2012
  • The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with such electric faults, specially short circuit faults. Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB), that is, Residual Current Protective Devices (RCDs) used on low voltage distribution lines cut off earth leakage and overload, but the RCD can not cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied in low voltage distribution panel are prescribed to rated breaking time about 30ms(KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To improve such problem, this paper proposes a prevention apparatus using the line voltage drop of neutral wire and some semiconductor switching devices. Some experimental tests of the proposed apparatus confirm the validity of the analytical results.

Development of Display Content for Overload Prevention in the Crane Controller (크레인 컨트롤러에서의 전도방지를 위한 디스플레이 콘텐츠 개발)

  • Lee, Sang Young
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.3
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    • pp.87-95
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    • 2012
  • Up to now, industrial cranes play important roles as the effective machines to carry heavy loads in the manufacturing premise, in the construction field and so on. And, a crane is widely used not only to daily work but also to carry heavy materials efficiently in a construction site for prevention of accident. However, the crane operation is highly complicated even for experts. In this paper, we developed the content of the crane mounted on the controller. This content overload conditions in the operating environment for the crane operator to warn, and the operation of equipment has the capability to limit automatically. The content for crane controller is to alert the operator overload and to limit the operation of equipment for stabilizing capabilities. The content of the flexible algorithm is based on stabilizing controllers, PLC (Programmable Logic Controller) to connect for using the equipment and electrical control systems to ensure the safety of workers and to improve the ability to work possible.

A Study on Development of Over-load Fault Prevention Apparatus using Distribution Line Voltage (배전선로 선로전압을 이용한 과부하 사고 예방장치 개발에 관한 연구)

  • Kwak, D.K.;Park, D.H.;Park, Y.J.;Jung, D.Y.;Kim, D.K.
    • Proceedings of the KIPE Conference
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    • 2012.07a
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    • pp.617-618
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    • 2012
  • Recently as the inactive response characteristics of the existing RCD(Residual Current protective Device) used on low voltage power distribution system, so control of overload and electric short circuit faults, major causes of electrical fires, are not enough. Therefore, this paper is proposed a prevention apparatus using neutral line voltage and semiconductor switching devices for the prevention of electrical disasters in low voltage power distribution system caused by overload or electric short circuit faults. The proposed prevention apparatus confirms the excellent characteristics in response velocity and accuracy in comparison with the conventional circuit breaker(RCD) through various operation performance analysis.

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Development of Overload Prevention Algorithm for the Crane Safety (크레인 안전을 위한 과부하 방지 알고리즘 개발)

  • Lee, Sang Young
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.2
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    • pp.11-19
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    • 2012
  • Crane systems have been widely used for transportation in building sites, ports, nuclear wastehandling operation and so on. As a typical underactuated system, an overhead crane has such merits as high flexibility and less energy consumption. And it's getting more types of cranes, universally applicable algorithms should be developed. That is the design and development of scalable algorithms are required. Developed algorithms can be used for the controller and crane overload protection that meets the requirements of the algorithm are presented. These algorithms force the state to warn the operator and stops the operation of equipment. In this paper, crane overload conditions that can cause damage to alert the operator, and to limit the operation of equipment overload protection algorithm is presented.

A Electrical Fire Disaster Prevention Device of High Speed and High Precision by using Semiconductor Switching Devices (반도체 스위칭 소자를 이용한 고속 고정밀의 전기화재 방재장치)

  • Kwak, Dong-Kurl
    • The Transactions of the Korean Institute of Power Electronics
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    • v.14 no.5
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    • pp.423-430
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    • 2009
  • Recently as the inactive response characteristics of the existing RCD used on low voltage power distribution system, so control of overload and electric short circuit faults, major causes of electrical fires, are not enough. Therefore, this paper confirms the unreliability of the existing RCD by electrical fault simulator and proposes a EFDPD by using semiconductor switching devices and a high precision current sensor (namely, reed switch) for the prevention of electrical disasters in low voltage power distribution system caused by overload or electric short circuit faults. The sensitive reed switch in the proposed EFDPD exactly detects the increased magnetic flux with the overload or the short current caused by a number of electrical faults, and the following, the self circuit breaker in EFDPD rapidly cuts off the system. The proposed EFDPD confirms the excellent characteristics in response velocity and accuracy in comparison with the conventional circuit breaker through various operation performance analysis. The proposed EFDPD can also prevent electrical disasters, like as electrical fires, which resulted from the malfunction and inactive response characteristics of the existing RCD.

A System IC for Controlling the Fire Prevention (화재방지제어 시스템 IC)

  • Kim, Byung-Cheul
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.4
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    • pp.737-746
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    • 2009
  • In this study, we have developed one chip system IC for preventing the overload, detecting an abnormal conditions, and controlling the fire prevention in the intelligent home appliances. For the purpose, a circuit detectable an electric leak for preventing an electric shock, and a circuit detectable arc that has effect directly on the fire are designed. The circuits designed on every block are verified by comparing simulation with bread-boarding using a standard transistors. The system IC is fabricated by using 34 V 2 metal $1.5{\mu}m$ bipolar transistor process from evaluation results. The electrical performances of IC application circuits and the system IC equipped on PCB board are evaluated. It is confirmed that the system IC is well operated for arc and ground fault(GF) signal.

Development of RCD Auxiliary Trip Device by using High Precision Current Sensor (고정밀 전류센서를 이용한 RCD 보조트립 장치 개발)

  • Kwak, Dong-Kurl
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.8
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    • pp.1532-1537
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    • 2009
  • Nowadays the diversity and large-capacity of electric appliances are strong effect on electrical fires augment in an alarming way. But, as the inactive response characteristics of the existing RCD (Residual Current protective Device) used on low voltage power distribution lines, so control of overload and electric short circuit faults, major causes of electrical fires, are not enough. Therefore this paper is confirmed the unreliability of the existing RCD by electrical faults simulation and is proposed a auxiliary trip device of RCD by using a high precision current sensor (namely, reed switch) for the prevention of electrical disasters in low voltage power distribution lines caused by overload or electric short circuit faults. The sensitive reed switch in the proposed ATD (auxiliary trip device) exactly detects the increased magnetic flux with the overload or the short current caused by a number of electrical faults, and then rapidly cuts off the existing RCD. The proposed auxiliary trip device of RCD is confirmed the excellent characteristics in response velocity and accuracy in comparison with the conventional circuit breaker through various operation performance analysis. The proposed ATD can also prevent electrical disaster, like as electrical fires, which resulted from the malfunction and inactive response characteristics of the existing RCD.

Development on Electrical Fire Prevention System of Small Size and High Speed by using PTC Thermistor (PTC 서미스터를 이용한 소형 고속응성의 전기화재 방재시스템 개발)

  • Kwak, Dong-Kurl
    • Journal of the Microelectronics and Packaging Society
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    • v.15 no.1
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    • pp.51-58
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    • 2008
  • This paper is studied on a prevention system for electrical fire and electrical faults by using electrical temperature characteristic of PTC thermistor. The PTC thermistor has characteristic of positive resistivity temperature coefficient according to the temperature variation, which is construction of a regular square and cube demarcation with $BaTiO_3$ ceramics of positive temperature coefficient. Also PTC shows the phenomenon which is rapidly increased in the resistivity if the temperature is increased over Curie temperature point. This paper is proposed on a protective control system used with temperature sensor of PTC thermistor. The proposed prevention system will prevent electrical fires due to electric short circuit faults or overload faults. And the prevention system will solve the problems that circuit breakers to be commonly used at existing are happened frequently electrical fires and electrical disasters due to incapable operation, weak reliability and low speed response. Some experimental results of the proposed apparatus are confirmed to the validity of the analytical results.

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