• Title/Summary/Keyword: Electrical Substation System

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A summary of KEPCO's 765kV substation design (한전 765kV 변전소의 기본설계 개요)

  • Kim, M.D.;Jung, S.H.;Kim, J.H.
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2139-2142
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    • 1999
  • 765kV substations which will be the core installation of the bulk power transmission system in Korea for the upcoming $21^{st}$ century, were designed of outdoor full GIS type to minimize required area. As principal equipment, main transformers of 2,000 MVA per bank and 50kA 8,000A gas insulated switchgears of up-to-date technology were adopted in designing substations to transmit bulk power of 10GW. Dual digital protective relay systems and distributed indication and control systems with fiber optic LAN were used.

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Dynamic Operational Strategies of UPFC in the KEPCO Transmission System

  • Chang, B.H.;Choo, J.B.;Lima, Leonardo T.G.;Feltes, James W.
    • KIEE International Transactions on Power Engineering
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    • v.3A no.3
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    • pp.168-176
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    • 2003
  • The Korea Electric Power Corporation (KEPCO) has installed an 80 MY A Unified Power Flow Controller (UPFC) at its 154㎸ 'Kang-Jin Substation in South Korea. The device, manufactured by Siemens & Hyusung, has been operational since October 2002. The Korea Electric Power Research Institute (KEPRI), a division of KEPCO was tasked to study operational strategies that could be employed for the UPFC and surrounding reactive support devices concerning problems of low voltages and overloads in the Mokpo & Gwangju areas. Particular apprehension surrounded the possibility of delay in the installation of a new 345㎸ transmission line from 2005 to beyond 2010. The studies were to specifically determine whether these problems could be eliminated by application of a UPFC. The analysis included determining the UPFC operating point under various conditions, investigations of the coordination between the UPFC and a HYDC line terminating in this area, and the design of a supplementary damping controller for the UFPC. This paper summarizes the results of those studies, demonstrating the dynamic characteristics of the operation of this UPFC operation in the Korean power system.

Analysis of voltage sag effect at load side during fault according to change of power system condition (계통조건(系統條件) 변경(變更)에 따른 고장시(故障時) 부하측(負荷側)의 순간전압강하(瞬間電壓降下) 영향분석(影響分析))

  • Yoon, Gi-Seob;Baik, Seung-Do;Gu, Sung-Wan;Lee, Chong-Soo;Lee, Hong-Gi
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.156-158
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    • 2002
  • In this paper, we analyze about voltage sag effect at load side during fault according to change of power system condition. through the case studies, we find that there is no close connection between substation bus transfer and voltage sag during fault. however, we find that other feeder connecting with the faulted transmission is directly affected by fault type and magnitude, therefore, the main subject can be divided into the utility and customer side countermeasures, utilities concentrate their effort to prevent the faults and to modify the fault clearing practice in power system. however, the faults in power system can never be completely eliminated. therefore, customer side solutions usually involve the power conditioning equipment for sensitive loads aiso, we investigate that the several methods to reduce the number and severity of voltage sag and to dull the sensitivity of equipment for voltage sag have developed. moreover, about SEMI, the industry association for the semiconductor two voltage sag immunity standards.(SEMI F47, SEMI F42) The simulation is accomplished by PSS/E 26.

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The Development of Gateway System for Power Automation based on TETRA (TETRA 기반 전력자동화 게이트웨이 시스템 개발)

  • Song, Byung-Kwen;Kim, Geon-Ung
    • Journal of IKEEE
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    • v.14 no.2
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    • pp.41-50
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    • 2010
  • TETRA is the standard of Digital Trunked Radio System suggested by the ETSI(European Telecommunications Standards Institut ). It is adopted as Electric Power IT Wireless Backbone Network in Korea. Police station and Fire Station are using TETRA network. Currently, Power Automation Protocols are DNP3.0 in Distribution Automation System, DLMS in Auto Metering Infrastructure, IEC61850 in Substation Automation. These protocols are transmissions using CDMA or WCDMA modem. If Power Automation protocol uses TETRA networks, it can be interoperable with the systems in police or fire stations. And it has outstanding ability to handle problems in a disaster situation. So, This paper propose a gateway system of Power Automation which can transmit the power automation protocol using TETRA.

Harmonics Assessment for an Electric Railroad Feeding System using Moments Matching Method (모멘트 정합 방법(Moment Matching Method)을 이용한 전기철도 급전시스템의 고조파 평가)

  • Lee, Jun-Kyong;Lee, Seung-Hyuk;Kim, Jin-O
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.1
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    • pp.1-7
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    • 2007
  • Generally, an electric railroad feeding system has many problems due to the different characteristics in contrast with a load of general three-phase AC electric power system. One of them is harmonics problem caused by the switching device existing in the feeding system, and moreover, the time-varying dynamic loads of rail way is inherently another cause to increase this harmonics problem. In Korea power systems, the electric railroad feeding system is directly supplied from the substation of KEPCO. Therefore, if voltages fluctuation or unbalanced voltages are created by the voltage and current distortion or voltage drop during operation, it affects directly the source of supply. The trainloads of electric railway system have non-periodic but iterative harmonic characteristics as operating condition, because the electric characteristic of the electric railroad feeding system is changed by physical conditions of the each trainload. According to the traditional study, the estimation of harmonics has been performed by deterministic way using the steady state data at the specific time. This method is easy to analyze harmonics, but it has limits in some cases which needs an assessment of dynamic load and reliability. Therefore, this paper proposes the probabilistic estimation method, moments matching method(MW) in order to overcome the drawback of deterministic method. In this paper, distributions for each harmonics are convolved to obtain the moments and cumulants of TDD(Total Demand Distortion), and this can be generalized for any number of trains. For the case study, the electric railway system of LAT(Intra Airport Transit) in Incheon International Airport is modeled using PSCAD/EMTDC dynamic simulator. The raw data of harmonics for the moments matching method is acquired from simulation of the LAT model.

A Study on the Protection System on the Electric Railways (전철급전회로 보호시스템에 관한 연구)

  • Chang, Sang-Hoon;Lee, Chang-Moo;Han, Moon-Seob;Oh, Kwang-Hae;Shin, Han-Soon;Kim, Jung-Hoon
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.1166-1169
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    • 1998
  • The Load characteristic of electric railway requires the power demand of the high capacity which amplitude is spacial-temporally fluctuated due to frequent starting and stopping with large tractive force. The conventional electric railway mainly consists of the resistance controlled and the thyristor controlled locomotives, are compensated for their bad characteristics of the power factor$(70\sim80%)$ with installation of another capacitor improving power factor at the substation. Since 1994, VVVF train car with good characteristics of power factor(100%) have been introduced and operated in Kwa-Chon Line. From the present technical tendency, it is judged that introduction of the locomotive with various controlled methods is necessary. The protective equipments installed at the substation are complicated and various aspects to detect faults and reduce their extension, so the universal countermeasures are required. Specially in the case of the fault occurrence it is difficult to calculate the fault location because of the change in the contactline constant according to modifying the characteristics of the contactline (the dualized catenary wire and extension, etc), so much time is required for the detection of fault location. In BT-fed method distance-relays and fault-locators are not installed, we have so many difficulties in the quick accident recovery.

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Implementation of on Expert System to Supervise GIS Arrester Facilities (GIS 피뢰설비 관리를 위한 전문가 시스템 구현)

  • Kil, Gyung-Suk;Song, Jae-Yong;Kim, Il-Kwon;Moon, Seung-Bo;Kwon, Jang-Woo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.1
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    • pp.75-81
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    • 2007
  • This paper dealt with the design and implementation of an expert system to monitor and diagnose the lightning arresters in GIS substations. The expert system consists of a data acquisition module(DAM) based on microprocessor and diagnostic algorithms. The DAM measures and analyzes several parameters necessary for the arrester diagnosis such as system voltages, leakage current components, and temperatures. Also, it includes an intelligent surge counter which can record the date and tin, the polarity, and the amplitude of surge currents. All the data acquired is transmitted to a remote computer by a low rate wireless network specified in IEEE 802.15.4 to avoid electromagnetic intereference under high voltage and large current environments. The decision-making for the arrester diagnosis completes with a Java Expert System Shell(JESS) which is composed of a knowledge base, an inference engine and a graphic user interface(GUI).

A Study on the Supply and Stray Current Distribution of the DC Railway Power System (직류전기철도 급전시스템에서 공급 및 누설전류 분포에 관한 연구)

  • Cho, Woong-Ki;Choi, Kyu-Hyoung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.6
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    • pp.160-168
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    • 2010
  • This paper presents the analysis of the current as stray current and supplied current of the substation, on the DC railway power system. In DC railway power supply system, the running rails are usually used as the return conductor(negative-polarity) for traction load current. This condition mainly focuses on economic considerations, since it does not require the installation of an additional return conductor. But, problems of low resistance between the running rails for the return conductor and earth allows a significant part of the return load current to leak into the earth. This current is normally called to as leakage or stary current. This stary currents creates serious problems for any electrified matter in the underground. Therefore, reduction of stray current of the DC railway power supply system is also of direct benefit to the operational and safety aspects of the DC railway systems. In this paper, deal with the analysis of the current distribution on the DC railway power system applied the common grounding system, using SPLIT of CDEGS program.

Hormonic Evaluation of An Imported IAT(Intra Airport Transit) System in Incheon International Airport (인천 국제공항청사 경전철 도입에 따른 고조파 영향 분석)

  • Kim, Jin-O;Song, Hak-Seon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.1
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    • pp.41-47
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    • 2006
  • This paper presents harmonic evaluation of an IAT(Intra Airport Transit) system in Incheon International Airport. It will be used for electric vehicles with 80[kW] per car produced by Mitsubishi Heavy Industries Ltd, and which is constructed with SIV(Static Inverter), VVVF controller and two induction motor. The vehicles operated in the IAT system can be treated as rapidly changing DC loat and at a feeding substation, 3-phase electric power is transferred to DC 750[V] by rectifier. Since vehicles are changing continuously, the voltages for the load fluctuate in the IAT system, and moreover, the voltage fluctuation generates high-order harmonics. It results the difficulty in maintaining power quality in KEPCO systems' side. The power quality of the IAT system in Incheon International Airport is evaluated using PSCAD/EMTDC simulator in the paper. The THD(Total Harmonic Distortion) of voltages and TDD(Total Demand Distortion) of currents, indices are calculated for the IAT system using the results of PSCAD/EMTDC dynamic simulation.

Analysis of Transient Characteristic in the Railway High Voltage Distribution Lines Using PSCAD/EMTDC at Method of Protection for One Line Ground Fault (PSCAD/EMTDC를 이용한 철도 고압 배전계통의 과도특성 해석 및 1선 지락사고에 대한 보호방안)

  • Park, Kye-In;Chang, Sang-Hoon;Choi, Chang-Kyu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.2
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    • pp.51-56
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    • 2008
  • High quality power supplying of high voltage distribution lines electric railway system is the important function, high voltage distribution system is complicated witch is compose with distribution line, circuit break, protection facilities and so on. Among this components, role of substation is most important for elevation of reliability in electric power system. Therefore, the enhanced reliability considering the preventive inspection, repair work replacement is necessary. This paper proposes protection method in railway high voltage distribution lines. we model distribution system using PSCAD/EMTDC(Power System Computer Aided Design/Electro Magnetic Transients DC Analysis Program) and extract various fault data. In conclusion this methods can protection of ground fault.