• Journal of Electrical Engineering and Technology
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• 제4권4호
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• pp.476-484
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• 2009

This paper deals with improvements to the special protection schemes (SPS) which have been applied to the low probability and high impact contingencies in the Korea Electric Power Corporation (KEPCO) system since 2004. Among them, the SPS for voltage instability in the Seoul metropolitan area is considered in this paper, and is a form of event-based undervoltage load shedding with a single-step scheme. Simulation results based upon a recent event that occurred on 765kV lines show that the current setting values of the SPS have to be revised and enhanced. In addition, by applying response-based multi-step undervoltage load shedding (UVLS) schemes to severe contingencies in the system, more effective results than those of the existing single-step SPS can be obtained. Centralized and distributed UVLS schemes are considered in the simulation. ULTC-based load recovery models and over excitation limiters (OXL) for the KEPCO system are also included in the long-term voltage instability studies.

• KEPCO Journal on Electric Power and Energy
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• 제5권1호
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• pp.17-24
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• 2019

본 논문은 전력계통의 부하 모델이 단기 전압 안정도 해석 결과에 미치는 영향을 분석하였다. 우선, 본 논문에서는 일반적으로 많이 사용되는 부하 모델을 소개하였고, 일부 부하 모델은 모델 파라미터를 최적화하더라도 실제 측정된 계통 현상을 재현할 수 없다는 것을 확인하였다. 또한, 본 논문에서는 상정사고 상황을 고려하여 국내 전력계통의 단기 전압 안정도 해석 시 부하 모델의 영향과 지역별 부하 모델의 영향성을 검토하였다. 해당 결과를 통해 부하 모델 선정의 중요성을 재차 확인할 수 있었으며, 상정사고 인근 지역의 부하 특성을 보다 더 정확하게 반영해야 함을 알 수 있다.

• 한국건설관리학회논문집
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• 제10권5호
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• pp.95-103
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• 2009

하천시설공사의 경우, 비정형적인 하천공사의 특성과 개략 공사비 산정을 위한 기준단가의 부재와 기본 설계단계 부재에 따른 가용정보의 부족 및 변동의 가능성 등의 특정으로 개략공사비 산정에 많은 어려움이 존재한다. 기존의 하천공사의 개략공사비 산정은 하천제방의 대표 단면의 물량 산출을 통한 대표 단면 공사비 산정 후, 이에 단순히 연장(m)을곱하는 방식을 적용하고 있다. 본 연구에서는 체계적인 개략공사비 산정 방법론이 존재하지 않는 하천공사의 개략공사비 산정 방법론을 제시하는데 있어, 기본설계가 없는 하천시설물공사의 특성을 고려해 기획단계에서의 개략공사비 산정 모델을 개발하고자 한다. 이를 통해 국가예산이 투입되는 공공공사에서 국가예산의 낭비를 방지하고, 보다 체계적이고 정확한 공사비 산출을 가능하게 하고자 한다.

• 응용통계연구
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• 제21권4호
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• pp.639-647
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• 2008

본 연구는 국민건강보험공단의 건강검진데이터, 자격 및 보험료 그리고 진료비 데이터를 활용하여 고혈압 관리를 위한 맞춤형 고혈압 사후관리모형(고혈압 진료예측모형 및 고혈압 진료순응도세분화모형)을 개발하고자 하였다. 모형 개발에는 데이터마이닝의 로지스틱 회귀모형, 의사결정나무 그리고 앙상블 모형을 활용하였다. 고혈압 진료예측모형에서는 3가지 모형 중 로지스틱 회귀모형이 가장 우수한 모형으로 채택되었으며, 고혈압 진료순응도세분화모형은 의사결정나무모형을 통해 개발되었다. 본 연구는 전국 규모의 수년간 축적된 자료를 데이터마이닝을 활용함으로써 고혈압의 진료 및 진료순응도에 이르는 고혈압 사후관리 프로세스 전반에 걸친 결과를 도출함으로써 우리나라 고혈압 사후관리체계 구축에 기여할 것으로 사료된다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2007년도 추계학술 발표회
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• pp.169-174
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• 2007

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.99-104
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• 1999

In 2000 FFIA , FIA, RDC are united into new corporation. This corporation will manage rural water with TM/TC(Tele-Monitoring/Tele-Control) system. Most systems which were adopted in TM/TC system were Closed Control System which use exclusive network and protocol . Closed Control System can not support new corporation's requirement in water management system. Therefore, new corporation should adopt Open Control System as standard rural water management system. Open Control System support Fieldbus technology, TCP/IP various protocols, programming model, OPC which is essential to the water management program, and so on.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.865-870
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• 1998

We propose a multifunctional power line compensator (PLC) which can individually compensate multiple impediments at the same time. The PLC has the flexibility to share power to each compensation according to commands, this improving the working rate. We constructed a 100kVA PLC model including a controller with digital signal processor (DSP) to realize a multifunctional compensation were obtained.

• 한국환경과학회지
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• 제24권4호
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• pp.515-524
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• 2015

The estimation of groundwater usage in Jeju island is important to understand hydrologic cycle system and to plan management of water resource because large amounts of groundwater have been used for agricultural and domestic purpose. The model has been developed to estimate agricultural groundwater usage for garlic at uplands and citrus at orchards raising outdoors using the soil water balance model from FAO 56, respectively. The total amount of water supplied for the crop evapotranspiration and the multipurpose function such as sprout promotion can be simulated by the model. However, due to the discrepancy of water use in initial stage between calculated and observed, the model was calibrated and verified using actual groundwater usage monitoring data for 3.5 years (2011.6 to 2014.12) at three uplands for garlic and three orchards for citrus. Consequently, it would be concluded that the model simulated efficiently actual water usage in that root mean square (RMS) and normalized RMS of the validation stage were less than 8.99 mm and 2.43%, respectively, in two different conditions.

• KEPCO Journal on Electric Power and Energy
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• 제2권2호
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• pp.233-244
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• 2016

Smart grid is called it as a system of systems. There are diverse types of systems in smart grid environment. Therefore, one of key factors to achieve smart grid successfully is interoperability among diverse systems. To secure interoperability, smart grid operating system should be developed complied with standards in terms of the data representation and communication. Common Information Model (CIM) and OLE Process for Control - Unified Architecture (OPC-UA) are the representative international standards in smart grid domain. Each standard defines data representation and communication by providing common information model and the unified architecture. In this paper, we explain a smart grid platform that we have developed to comply with CIM and OPC-UA standards for secure interoperability among numerous legacy systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.363-365
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• 1999

800kV GIS(Gas Insulated Switchgear) was first developed by Hyosung Corporation in Korea at Dec. 1998 and is going to be installed first in the Dangjin Thermal Plant. We intoned to verify the structural safety of 800kV GIS under seismic load. The modal analysis of 800kV GIS has been carried out to obtain the natural frequency and mode shape. PATRAN was used for mode)ing exactly 800kV GIS Geometry. 800kV GIS FE(Finite Element) model was constructed of shell elements for the enclosures and beam elements for the conductors and the support insulators NASTRAN was used for analyzing the normal modes of 800kV GIS FE model.