• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1997-2004
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• 2011

The $2{\times}25kv$ AT electric power feeding method in the A.C. electric train adopts the one-phase power feeding method as the standard due to a voltage phase difference, and the distance between the two neighboring substations is 50km due to voltage drop. The one-phase power feeding method makes the system operation feasible, while making it unfavorable for power supply. Moreover, railroad involves large-capacity single-phase load, and if it is expected to continue to rise, it is necessary to research on measures to stabilize the supply of power to railroad cars with the existing facilities. In this study, a parallel power feeding method between neighboring substations is proposed to stabilize the supply of electric power to electric railroad cars under the 2*25kv AT power feeding method and the loop current induced by voltage phase difference between the two neighboring substations during parallel power feeding is investigated.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.836-845
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• 2007

In DC 1500V electric traction substations, diode rectifiers are commonly used to supply stable DC power with electric train sets. However, it operates in the first quadrant of the voltage-current plane and thus needs regenerative inverters which transfer the surplus regenerative power caused by regenerative braking of electric train sets into the grid. In order to select the proper capacity and installation position of regenerative inverter, it needs to investigate the consumed and regenerative energy of the electric traction substations in advance. This paper presents an analysis of regenerative energy in two substations operating in Seoul line 2 and Kwangju line 1. DC line voltage and feeder currents are measured for a day to calculate consumed and regenerative power for four feeders. We calculated an amount of regenerative energy consumed in other feeders and estimated the cost reduction in energy consumption due to the reuse of regenerative energy.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 추계 학술발표회논문집
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• pp.66-73
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• 2003

The technique for the seismic reliability evaluation of the electric power network is presented. In the previous study, the state of the substations was represented by the bi-state which is classified as failure or survival. However, the hi-state model can result in oversimplified analysis, because substations are worked by the parallel operating system. In this paper, Considering the characteristics of the parallel operating system, the damage of the substation is expressed by the multi-state for the more realistic seismic reliability evaluation. Using Monte-Carlo simulation method, the seismic reliability for Korean 345㎸ electric power network is evaluated. Analysis results show that reliability levels of the network by the multi-state analysis is higher than that by the hi-state analysis and the electric power network in southeastern area of the Korean Peninsular may be vulnerable to earthquakes.

• 대한전기학회논문지
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• 제39권2호
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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.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권9호
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• pp.478-484
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• 2006

The paper presents methods of determining the capacity and installation positions of regenerative inverters installed in DC 1500V electric railway system. We suggested a method that approximates using parameters related to substations where regenerative inverters are installed, railway lines and operating motor cars, and another that calculates using regenerative power obtained from Train performance Simulation (TPS) and Power Flow Simulation (PFS). We carried out TPS and PFS for Seoul Subway Line $5{\sim}8$, calculating regenerative power and determining substations where regenerative inverters would be installed and the optimal capacity and number of inverters to be installed.

• 한국철도학회논문집
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• 제10권6호
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• pp.717-722
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• 2007

본 논문에서는 직류 1500V 지하철 변전소의 가선전압과 피더별 전류량을 측정한 결과를 분석한다. 선릉과 양동시장 변전소들의 피더별 소비 및 회생전력을 측정하고, 피더별로 발생된 회생전력이 타 피더로 전달되는 전력량을 계산하였다. 전철변전소에서 회생전력이 교류될 수 있는 거리를 타 변전소와의 중간지점으로 가정하고, 전동차 1편성의 회생전력량을 기초로 변전소에서 발생되는 총 회생전력량을 근사식으로 계산하였다. 이렇게 얻어진 값과 측정된 피더간 교류된 회생전력량을 사용하여 변전소의 회생전력 실효전력량을 계산하고 회생인버터가 설치된 후 재활용할 수 있는 회생전력량을 근사적으로 얻었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1861-1863
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• 1996

In this paper, measurements and analyses of ELF electric fields in the vicinity of UHV overhead transmission lines and substations have been conducted. Planar-type sensors have been developed with special consideration of picking up lower frequency and spatial components without any distortion. So finally the electric field measuring system has the frequency bandwidth of 7[Hz] to 2.7[MHz] and the response sensitivity of 0.094[mV/V/m]. A brief description of design rules of the measuring system and measurement procedures is introduced. The actual survey near 154 and 345[kV] overhead transmission lines and power subststions was carried out and analyzed. It may be inferred from these results that the electric field intensity exeeds 7[kV/m] only in very few cases particularly at the substations so that the field measurements meet almost limits or guidelines that various authorized international institutes recommend.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1885-1887
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• 2000

In this paper we introduce preventative and diagnostic systems developed to prevent substations from accidental fault of electric power transmitting apparatus. We propose monitoring and diagnostic system for ultra high voltage GIS and main transformer of 765kV substations as an example of preventative and diagnostic techniques being applied in Korea. We also present a guideline to construct and manage an expert system for this purpose. Finally, an engineering solution as a substation management support system is proposed.

• 조명전기설비학회논문지
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• 제24권6호
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• pp.27-34
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• 2010

본 연구는 변전소(사무실) 비상 및 복구등 설비환경 개선차원으로 실시하였다. 기존 비상등의 낮은 조도로 인해 발생하는 문제점을 해결하기 위해 AC/DC 겸용 형광등 안정기 및 스위치를 연구하였다. 또한 조도기준을 상시등의 5~10[%]가 아닌 한국산업규격 조도기준(KS A 3011)에 따른 원자력발전소 조도기준과 안전조명 조도기준을 참고로 변전소 각 실별 조도기준을 제안하였다. 마지막으로 본 연구에서 제안한 내용의 타당성을 검토하기 위해 실험을 하였다. 그 결과 축전지 용량을 증가시키지 않으면서도 비상 및 복구등의 조도를 높일 수 있었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.3117-3123
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• 2011

도시철도의 전동차는 변전설비로부터 전력을 공급받아 지상, 지하부의 다양한 선로조건(구배)를 지닌 선로를 운행하며, 열차 제동 시 많은 회생전력이 발생하고 있다. 회생제동은 에너지를 재활용 할 뿐만 아니라 기계식 브레이크의 사용을 줄이는 매우 이상적인 시스템이라고 할 수 있다. 또한 중요한 점은 회생제동이 가능한 시스템은 발생된 에너지가 어떤 정해진 흐름을 가지고 소모되고 재활용 가능하다는 것이다. 본 연구에서는 서울도시철도 전력공급소(변전소)의 전동차용 전력의 정밀분석을 실시하였다. 이를 통하여 변전소 전력공급과 전동차 전력사용의 데이터 분석을 통하여 회생전력 활용 연구의 기반작업을 수행하였다.