• Title/Summary/Keyword: Feeder current

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The Influence on Traction Return Current by Pantograph Detachment Frequency of High-speed Train (고속철도차량의 이선빈도가 귀선전류에 미치는 영향)

  • Lee, Sung-Gyen;Cho, Young-Maan;Ko, Kwang-Cheol
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.9
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    • pp.8-13
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    • 2014
  • Currently it is major problem of electric railway with increasing drive speed such as the arc generated by the pantograph detachment and the distortion current in the motor-block high speed switching. When physical contact between the pantograph and the catenary line is separated, the pantograph detachment arcing occurs and it makes up the conductive noise to the return feeder. We made the EMTP modeling of the railway traction system and the pantograph arc by circuit elements and switches. The influence of pantograph detachment frequency is investigated by changing some frequencies. The over-current occurs in each detachment and it oscillates some time at beginning and stabilizes gradually. The magnitude of over-current is decided by instantaneous value of existing traction return current. If the detachment occurs at a point of peak value or distortion current, the over-current will be more harmful to the power systems connected with the return feeder and will become to arise with increasing detachment frequency.

A Study on Causes and Measures Against Occurrence of Circulating Current in catenary (전차선로 순환전류 발생원인과 대책에 관한 연구)

  • Han, Hag-Su;Min, Kyung-Yun
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.816-823
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    • 2007
  • Electric car tract plays the role of supply high electric power to the electric car from the substation by using Pantograph of the electric car. It is always exposed to the external atmosphere, which results in quite substantial fluctuations in current and voltage during operation of electric car. This generates possibility of occurrence of accident at all times. Since range of wiring metallic globe installed on the catenary cannot achieve complete electrical contact, accidents are occurring due to circulating current caused by arc caused by incomplete contact due to occurrence of hairline fracture of Pantograph due to pressure or vibration of wiring. Furthermore, rapid increase in the operational current due to increase in the operational frequency of the electric car is causing erosion and short circuit of the metallic globe at the contact points. This study on arc is generated as current transmitted out of the substation courses through power line or wiring metallic globe other than the main circuit as the current is being collected at the electric car through feeder and feeder divergence device. Accordingly, since heat generated by the arc becomes the cause for generation of circulating current due to melting of metal or softening of metal due to increase in temperature accompanying increase in contact resistance, this research shall describe causes and measures against occurrence of circulation current.

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Voltage Quality Analysis in Power Distribution System with Superconducting Fault Current Limiter at Grounding Line (초전도 한류기를 주변압기 접지선에 설치시 배전계통의 순간전압품질 분석)

  • Moon, Jong-Fil
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.4
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    • pp.159-163
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    • 2013
  • In this paper, voltage quality improvement is analyzed in case of Superconducting Fault Current Limiter (SFCL) installed in grounding line of main transformer in power distribution system. First, a resistive-type SFCL model is used. Next, Korean power distribution system is modeled. Finally, when SFCL is installed in the starting point of feeder and grounding line of main transformer, voltage qualities are evaluated according to various fault locations and resistance values of SFCL using PSCAD/EMTDC. The voltage quality results in case of grounding line are compared with the voltage in case of feeder.

A Study on the Improvement of Fault Detection Capability for Fault Indicator using Fuzzy Clustering and Neural Network (퍼지클러스터링 기법과 신경회로망을 이용한 고장표시기의 고장검출 능력 개선에 관한 연구)

  • Hong, Dae-Seung;Yim, Hwa-Young
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.3
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    • pp.374-379
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    • 2007
  • This paper focuses on the improvement of fault detection algorithm in FRTU(feeder remote terminal unit) on the feeder of distribution power system. FRTU is applied to fault detection schemes for phase fault and ground fault. Especially, cold load pickup and inrush restraint functions distinguish the fault current from the normal load current. FRTU shows FI(Fault Indicator) when the fault current is over pickup value or inrush current. STFT(Short Time Fourier Transform) analysis provides the frequency and time Information. FCM(Fuzzy C-Mean clustering) algorithm extracts characteristics of harmonics. The neural network system as a fault detector was trained to distinguish the inruih current from the fault status by a gradient descent method. In this paper, fault detection is improved by using FCM and neural network. The result data were measured in actual 22.9kV distribution power system.

Inverted π Feeding PIFA for Gain Improvement for the Mobile Phone (이득 증가를 위한 휴대 단말기용 역 파이 급전 PIFA)

  • Son, Tae-Ho;Lee, Jae-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.12
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    • pp.1337-1344
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    • 2007
  • It is shown that inverted ${\pi}$ feeder affects the gain improvement for the internal antenna of mobile phone. Generation of current on the inverted ${\pi}$ feeder, by the modification of conventional feeding structure for the PIFA and IFA, can apply T matching theory to the new feeder. Therefore, inverted ${\pi}$ feeder based on the T matching theory makes higher radiation resistance, and also increases the gain. To verify inverted ${\pi}$ feeding effect, feeder is applied to GSM/DCS dual band conventional PIFA, and measured return loss and patterns. By measurement, it's shown that this new feeding antenna has $0.23{\sim}0.84$ dB higher average gain for GSM band and $0.01{\sim}1.74$ dB higher average gain for DCS band than conventional fed PIFA without resonant frequency change.

Analysis of Feeder wire fault Scenario on AC Railway Feeding System considering Train Position (전차 위치를 고려한 교류 전기철도 급전계통의 급전선 고장 시나리오 해석)

  • Huh, Seunghoon;Cho, Gyujung;Ryu, Kyusang;Lee, Hundo;Kim, Chulhwan;Min, Myunghwan;An, Taepung;Kwon, Seongil
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.272-273
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    • 2015
  • This paper analyze scenario of feeder wire fault that occurs in the AC feeding system considering train position. The fault location of AC feeding system is calculated by measuring impedance. However, in this way, estimation error can be occurred because of tie connection, boosting current, etc. Therefore, it's hard to find fault location, so that it is required to detailed circuit analysis according to fault location. We analyze the short circuit impedance values with respect to feeder wire fault according to a train position. In this paper, PSCAD is used for modeling and analysis of AC railway feeding system.

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An Effective Utilization of Regenerative Power According to the Output Voltage of Substations in the DC Electric Railways (직류전기철도 시스템에 있어서의 변전소 송출전압에 따른 회생전력유효이용)

  • Kim, Yang-Mo
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.2
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    • pp.149-156
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    • 1990
  • In DC electric railway systems, the feeding currrnt is not permitted to flow backward in almost all the substations and the pantograph voltages at the regenerating cars rise extremely by the voltage drop of the resistance of the feeder line. In order to prevent the overrise of the pantograph voltage in power regenerating cars, the squeezing circuits for the regenerative current are equipped and this leads to double losses, which are an extra worn-out of the brake-shoes and an ineffective use of regenerative power. In this study, the insertion of resistors in the feeder line system is proposed as a possible method for the effective utilization of the regenerative power in the electric railways. Also it is investigated how the output voltages of substations affect the effective use of regenertive capability. The investigation results show that the energy savings and the reduction of the worn-out of the brake-shoe can be achieved at the same time by the insertion of resistors in the feeder line system.

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The feeder automation process of new distribution automation system (신 배전자동화 시스템의 배전선로 고장인지 및 분석방법)

  • Ha, Bok-Nam;Han, Yong-Huei;Lee, Jung-Ho;Cho, Nam-Hun;Lim, Seong-Il
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.125-127
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    • 1999
  • We generally use Yes-No algorithms for feeder automation algorithm. This logic determines the faulty section by fault current detection information of the fault indicators of each switches in distribution feeder. This paper presents the data acquisition method such as breaker's open status in fault and the determination method of faulty section using fault indicator's information of each switches.

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The Algorithm for Feeder Automation in the New Distribution Automation System (신 배전자동화시스템의 배전선로 고장처리 알고리즘)

  • Ha, Bok-Nam;Lee, Jung-Ho;Cho, Nam-Hun
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.841-843
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    • 1998
  • The second project of the development of distribution automation system was started recently in Korea. We will use two algorithms for feeder automation in this project. The one is Yes/No logic and it will be applied in large city. Yes/No logic determined the faulty section by fault current following information of the fault indicators of each switches. The other is automatic closing process of switches, and it will be applied in rural area. In the latter method, each switches close systematically, and it can find and separate the faulty section, the computer system treats only the feeder reconfiguration finally.

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IPI feeding structure for the gain improvement of IFA (IFA 이득 향상을 위한 IPI 급전 구조)

  • Oh, Kyu-Jong;Son, Tae-Ho
    • Journal of Advanced Navigation Technology
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    • v.14 no.6
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    • pp.817-823
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    • 2010
  • Design of IPI feeding structure affecting the antenna gain improvement of mobile phone was investigated. IPI feeder which based on the T matching theory increase line current for internal antenna such as IFA. So IPI feeder makes higher radiation resistance, and also increases the gain with increasing radiation efficiency. To verify IPI feeding effect, feeder is applied to conventional CDMA/DCS dual band IFA. Measurement shows that IPI-IFA has 0.5 ~ 1.4[dBi] higher gain than conventional IFA at CDMA/DCS band. Resonant frequency did not change.