• Title/Summary/Keyword: Short-circuit current

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The Causes and Analysis of Electrical Fires -focused on Dynamic Characteristics of RCD- (전기화재의 발생원인 및 분석 -누전차단기의 동작특성을 중심으로-)

  • 이상호
    • Fire Science and Engineering
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    • v.17 no.2
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    • pp.1-5
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    • 2003
  • Recently, the occurrences of electrical fire have been suppressed by a residual current protective devices(RCD), a molded case circuit breaker(MCCB) and a fuse in case of an earth leakage, a short circuit and an over current. But it is impossible for the RCD to break the circuit in the case of the conductor fractures, the failure of pressure contacts on connecting points and the momentary short circuit of low voltage wiring. Therefore, it is require to study the constructive problem of the RCD. In this paper, we have tested the operation characteristics of the RCD according to the R load and R-L load in the conductor fractures, the failure of pressure contacts on connecting points and the momentary short circuit of low voltage wiring.

Selection of Capacity of Circuit Breaker by Probabilistic Short-Circuit Current Analysis (확률적 고장전류 해석에 의한 차단기 용량 선정)

  • 문영현;오용택
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.1
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    • pp.10-15
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    • 1990
  • This paper presents an algorithm that can compute equivalent impedance effctively in computing 3-phase short circuit current which would be generated in power systems. Also this paper proposes a method that can decide the capacity of circuit breaker by analysing the fault current distribution probabilistically when the fault point of specificed line varies. The efficiency of the algorithm was verified by applying the proposed method to IEEE-6bus system and IEEE-30bus system, and probabilistic fault analysing method is verified economic in facility investment by deciding the proper capacity of circuit breaker.

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Analysis on Fault Current Limiting Characteristics of Flux-Lock Type SFCL Using Magnetic Flux Application Circuit (자기인가회로를 이용한 자속구속형 초전도한류기의 고장전류제한 특성 분석)

  • Go, Ju-Chan;Lim, Seung-Taek;Lim, Sung-Hun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.1
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    • pp.37-41
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    • 2017
  • In this paper, the fault current limiting characteristics of the flux-lock type SFCL (superconducting fault current limiter) using magnetic application circuit were analyzed. The flux-lock type SFCL has the structure to install the magnetic application circuit, which can increase the resistance of HTSC ($high-T_C$ superconducting element comprising) the SFCL. To analyze the fault current limiting effect of the flux-lock type SFCL through the magnetic flux application circuit, the flux-lock type SFCL either with the magnetic flux circuit or without the magnetic flux circuit was constructed and the fault current limiting characteristics of the SFCL were compared each other through the short-circuit tests.

A Study on the Characteristics of Short Circuit through the Cross Section Analysis of Electric Wire (전선의 단면분석을 통한 단락특성에 관한 연구)

  • Shong, Kil-Mok;Choi, Chung-Seog;Kim, Yun-Hoi;Kim, Sang-Hyeon;Park, Nam-Kyu
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.51-56
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    • 2005
  • For a fire cause judgement this paper describes the short circuit characteristics of a electric wire through the cross section analysis under ac condition. The cower wires prepared for the experiment were 1.2mm, 1.6mm, and 2.0mm in diameter. Through the cross section analysis(CSA), it was confirmed that the dendrite structure grew at the angle of about $40^{\circ}\;or\;60^{\circ}$ when the fusing current was applied to the wires. The larger the fusing current is, the more decreased the growth angle of the dendrite structure is. It was confirmed that the dendrite structure was arranged like the columnar structure. In this paper, the characteristics analysis of short circuit was carried out in the range of transient duration and the correlation constant k was investigated by measuring the short circuit duration and the fusing current.

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Measurements of X-Ray and Gamma Ray Dosse Rate by the Silicon P-N Junction Diode (Silicon P-N Junction Diode에 대한 X-Ray 및 Gamma-Ray 의 Dose Ratec 측정)

  • 정만영;김덕진
    • 전기의세계
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    • v.13 no.3
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    • pp.13-20
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    • 1964
  • The measurements of X-ray and Gamma-ray Dose Rate have been successfully made by measuring the short circuit current of the Silicon P-N Junction Diode being irradiated. The short circuit current flows when a silicon P-N Junction Diode is irradiated by X-ray of Gammaray radiations due to photovoltaic effect. A brief analysis is given in order to verify the proportionality of a short circuit current to the Dose Rate. Using this method, measurements of X-ray Dose Rate were carried out in the range of 0.05-1600 r/m successfully. The calibration was made by comparing with Victoreen condenser r-meter. Some advantages in this Dose Rate meter over a condenser r-meter were found. One can measure a continous variation of X-ray Dose Rate with this rate meter at the control console of X-ray device.

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A New Dual Gate Transistor Employing Thyristor Action (사이리스터 동작을 이용한 새로운 이중 게이트 트랜지스터)

  • 하민우;전병철;최연익;한민구
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.7
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    • pp.358-363
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    • 2004
  • A new 600 V dual gate transistor employing thyristor action, which incorporates floating PN junction and trench gate IGBT, is proposed to improve the forward current-voltage characteristics and the short circuit ruggedness. Our two-dimensional numerical simulation shows that the proposed device exhibits low forward voltage drop and eliminates the snapback phenomena compared with conventional trench gate IGBT and EST The proposed device achieves high current saturation characteristics by separating floating N+ emitter and cathode. The proposed device achieves low saturation current value compared with conventional devices, and the short-circuit ruggedness is improved. The proposed device may be suitable for the use of high voltage switching applications.

Macromodel for Short Circuit Power and Propagation Delay Estimation of CMOS Circuits

  • Jung, Seung-Ho;Baek, Jong-Humn;Kim, Seok-Yoon
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.1005-1008
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    • 2000
  • This paper presents a simple method to estimate short-circuit power dissipation and propagation delay for static CMOS logic circuits. Short-circuit current expression is derived by accurately interpolating peak points of actual current curves which is influenced by the gate-to-drain coupling capacitance. The macro model and its expressions estimating the delay of CMOS circuits, which is based on the current modeling expression, are also proposed after investigating the voltage waveforms at transistor output modes. It is shown through simulations that the proposed technique yields better accuracy than previous methods when signal transition time and/or load capacitance decreases, which is a characteristic of the present technological evolution.

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Implementation of ELB Leakage Current Control System based on ZigBee Communication (ZigBee통신 기반 ELB 누전전류 제어시스템 구현)

  • Ju, Jae-Han
    • 전자공학회논문지 IE
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    • v.49 no.2
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    • pp.52-57
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    • 2012
  • Social development as well as the development of consumer electronic devices due to leakage, electric shock or fire, and many are exposed to the risk of leakage currents. Premises in the control cabinet, but the circuit breaker is installed, the existing circuit breaker shuts off when a short circuit in the control cabinet, installed only have the capability. Also connected to the outlet is installed byeokmada family of devices is not easy thing to check individually. In this paper, circuit breakers and circuit analysis and circuit performance, ZigBee-based premises of consumer electronics devices using sensors to monitor the health of the leakage can be presented on how. Performance analysis, the proposed ELB leakage current control system is built into the appliance leakage circuit breaker for each household appliances because the application can check the status of a short circuit, short circuit, over the existing system can be monitored easily.

The Study of Comparison with ANSI/IEEE and IEC for Short Circuit Test of Transformers (ANSI/IEEE와 IEC 규격(規格)에 따른 변압기(變壓器)의 단락강도시험(短絡强度試驗)의 비교(比較))

  • Kim, Sun-Koo;Kim, Sun-Ho;Kim, Won-Man;La, Dae-Ryeol;Roh, Chang-Il;Lee, Dong-Jun;Jung, Heung-Soo
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.705-706
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    • 2006
  • Generally Short Circuit Test of transformers are tested according to IEEE std C57.12.00-2000, IEC 60076-5(2000-07), ES148(1998.6.26) or KS C4309(2003). But ES148(1998.6.26) is same as IEEE std C57. 12.00-2000 and KS C4309(2003) is revising coincidence with IEC 60076-5(2000-07). On this study condition of the transformers before short circuit test, calculation method for test current peak value, tolerance on the asymmetrical peak and r.m.s value, short circuit testing procedure, number of short circuit test, duration short circuit test, and detection of faults and evaluation of short circuit test result will be compared with ANSI and IEC.

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Probeless Estimation of Electroluminescence Intensities Based on Photoluminescence Measurements of GaN-Based Light-Emitting Diodes

  • Kim, Jongseok;Jeong, Hoon;Choi, Won-Jin;Jung, Hyundon
    • Current Optics and Photonics
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    • v.5 no.2
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    • pp.173-179
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    • 2021
  • The electroluminescence (EL) intensities of GaN-based light-emitting diodes (LEDs) are estimated based on their photoluminescence (PL) properties. The PL intensity obtained under open-circuit conditions is divided into two parts: the PL intensity under a forward bias lower than the optical turn-on voltage, and the difference between the PL intensities under open-circuit conditions and under forward bias. The luminescence induced by photoexcitation under a constant forward bias lower than the optical turn-on voltage is primarily the PL from the excited area of the LED. In contrast the intensity difference, obtained by subtracting the PL intensity under the forward bias from that under open-circuit conditions, contains the EL induced by the photocarriers generated during photoexcitation. In addition, a reverse photocurrent is generated during photoexcitation under constant forward bias across the LED, and can be correlated with the PL-intensity difference. The relationship between the photocurrent and PL-intensity difference matches well the relationship between the injection current and EL intensity of LEDs. The ratio between the photocurrent generated under a bias and the short-circuit current is related to the ratio between the PL-intensity difference and the PL intensity under open-circuit conditions. A relational expression consisting of the ratios, short-circuit current, and PL under open-circuit conditions is proposed to estimate the EL intensity.