• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.907-910
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• 1992

This paper deals with the mesurement and the analysis by means of EMTP simulation for the fast-rising switching surges. The fast-rising surges having up to 180ns of front time and 3.42 p.u of peak value were measured at the 154KV substations. The fast-rising surges are expected to cause electric breakdown because the penetrating surges to the transformers result in the higher stress in the winding end than the average stress along the winding.

• 전기학회논문지
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• 제59권8호
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• pp.1382-1387
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• 2010

Recently, there has been a growing interest in the environmental conservation. Accordingly, problems related to the audible noise of transformers have became more frequent. Therefore, it is urgent to find a fundamental solution about the audible noises in the substations. This paper described a sort of fundamental solution to solve the noise problem. As a fundamental solution, we suggested the proper audible noise level of transformers through noise prediction in the substation construction phase. And we applied the low noise transformers which have the predicted noise level. As the result, we are able to satisfy the noise regulation through measuring 43.6dBA at the boundary of substation. It is confirmed that the average error rate of prediction was within 3 percent.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.353_354
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• 2009

변전소내 주 전력설비에는 변압기, 170kV 및 25.8kV GIS(Gas Insulated Switchgear), 보호제어장치, 집중감시제어반, SCADA(Supervisory Control and Data Acquisition) 등으로 구성되어 있다. 이들 기기들을 제어하고 조작하기 위한 조작회로 보조장치에는 접자접촉기인 보조계전기가 사용되어진다. 1개 배전반내에 보조계전기는 보통 20개 이상 설치되어 있고 변전소내 타 고가 전력기기에 비해 저가이고 수량이 상대적으로 매우 많다. 본 논문에서는 25.8kV GIS내에 널리 사용되는 일반 제품인 보조계전기의 특성을 고찰하므로서 변전소 운전환경에 적합한 운영방안을 제시하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.143_144
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• 2009

본 논문은 우리나라 전력계통의 345kV 변전소에 대한 전압운영기준을 제시하여 준다. 전압운영기준을 개발하기 위해 2차 전압제어이론을 적용하였고, 지역구분을 위해서는 CESI 알고리즘을 사용하였다. 본 검토에 사용된 계통검토용 PSS/E 기본파일은 실계통 운전실적 데이터를 사용하였고, 지역별 대표모선에 대한 기준전압은 최적조류계산을 사용하여 계산하였다. 각 제어지역별 전압범위와 제어기준들은 다양한 조건하에서의 EMS 운전실적 데이터 분석을 통해 제시되었다.

• 조명전기설비학회논문지
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• 제23권3호
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• pp.30-37
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• 2009

The majority of the causes for the failures of power transformers in operation are mechanical defects due to vibration. The vibration phenomenon was measured from the power transformers in operation in the substations. The vibration measurement was performed in a $6{\times}4$ structure on one side of each transformer. The vibrations of the measured points were presented in two and three dimensions and analyzed. The results, according to the elapsed year of the transformer and the load capacity to the transformer, were analyzed. These results could be used as basic data with which to establish vibration standards for power transformers. In addition, the load capacity-vibration phenomenon correlation was examined and regression analysis was performed to derive the estimation function. The vibration phenomenon according to the elapsed yeah was also estimated to derive the function. Then the analysis of the power transformers was used to set vibration standards for them based on the vibration data.

• 조명전기설비학회논문지
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• 제29권7호
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• pp.14-21
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• 2015

Distribution systems are operated in radial structure, but temporal loop structure could be founded the live load transfer. Main purposes of reconfiguration of distribution network are load balancing, loss minimization and voltage drop maintaining. In the loop structure, huge loop current can be flowed between two substations in case of large voltage angle difference. Protection devices of distribution line can be triped by this huge loop current. So, precise calculation of loop current is very important for secure switching. This paper proposes a novel calculation method of loop current using the voltage angle differences measured at the tie switches. Feasibility of the propose method has been verified by various case studies based on Matlab simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.304-306
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• 2000

Load modeling, micro method, needs field test to identify the validity of methodology applied to modeling. This paper presents seasonal field test method and measurement results on serveral substations. Seasonal load characteristics were analyzed by the developed substation load model and correlation coefficients of seasonal load of substation under base, peak and average load time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.116-118
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• 2000

The modern power system including lots of measuring devices and controller is large and complex total information system. A Lot of data and system information are transmitted to operators, and analysing these information and system management is very important. Recently, GUI(Graphic Users Interface) is emphasized as a method that operators carry out their duties, effectively. In this paper. a simulator that can show state estimation and detection of bad measuring devices is introduced for domestic 154kV/22.9kV distribution substations. C language and Visual Basic is used for this simulator. and TCP/IP is adopted to consider connection with a Power system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.592-596
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• 2005

The preventive diagnostic system prevents transformers from power failure by giving alarm and observing transformers in service. And it helps to establish the plan for optimum maintenance of transformer as well as to find location or cause of fault using accumulated data. KEPCO has adopted the preventive diagnostic system at nine 345kV substations since 1997. Techniques for component sensors of preventive diagnostic system were settled but diagnostic algorithm, diagnostic criteria and practical use of accumulated data are not yet established. This paper, to build up the base of preventive diagnostic algorithm for the power transformer, investigated the preventive diagnostic criteria for power transformer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.38-39
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• 2006

KEPCO is executing a project in Cambodia consisting of two components, "Power Development Master Plan and Institutional Strengthening" and "Greater Mekong Sub-region (GMS) Power Project Preparation" upon request by the government of the Ministry of Industry, Mines and Energy of Cambodia, contracted on $29^{th}$ September 2005. This paper includes a basic design and review of economical efficiency for constructing the two (2) cross border 115 kV transmission lines, which run from the border of Vietnam and Laos to Cambodia, and four (4) 115kV substations. The main contents of the paper include the process of design and results of a review of line route selection, tower and hardware design regarding transmission line design, as well as the type of substation, and arrangement and specifications of equipment with expects to substation design. Also, long-term demand forecasting, and an economic analysis of the project area are included.