• 전기학회논문지
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• 제59권10호
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• pp.1733-1740
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• 2010

KPX(Korea Power Exchange) predicts that summer peak load will be 70,700MW and system overload will be 150% from contingency analysis. This paper presents a method to operate power system at 2010 summer peak. about equipment variation, power system variation, analysis results of voltage stability, and the method to relief overload by comparing 2009 and 2010. Especially, transmission constraints to prevent global contingency in Korea power system and the role of SPS(Special Protection System) to prevent voltage collapse when fault occurs are introduced.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.152-155
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• 1991

The analysis and forecast of summer cooling load is one of the major concerns of utility company(KEPCO). In this paper, various methodologies to assess the weather sensitive load are introduced and the cause of remarkable growth of the summer cooling load in the last years are analized. To establish the effective measures to migrate the peak building by the summer cooling, a number of practical institutional policies are offered for future implementation.

• 전기학회논문지P
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• 제55권1호
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• pp.35-40
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• 2006

Heat-pump system has a special feature that provides heating operation in winter season and cooling operation in summer season with a single system. It also has a merit that absorbs and makes use of wastewater heat, terrestrial heat, and heat energy from the air. Because heat-pump system uses midnight electric power, it decreases power peak load and is very economical as a result. By using the property that energy source is converted to low temperature when losing the heat, high temperature energy source is used to provide heating water and low temperature energy source is used to provide cooling water simultaneously in summer season. This study made up a heat-pump system with 4 air heat sources and a water heat source and implemented the optimal operation algorithm that works with numbers of heat pumps to operate them efficiently. With the heat-pump system, we applied it to cooling and heating operation in summer season operation mode in a real building.

• 전기학회논문지
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• 제62권4호
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• pp.482-488
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• 2013

Load forecasting is essential to the economical and the stable power system operations. In general, the forecasting days can be classified into weekdays, weekends, special days and special light-load periods in short-term load forecast. Special light-load periods are the consecutive holidays such as Lunar New Years holidays, Korean Thanksgiving holidays and summer special light-load period. For the weekdays and the weekends forecast, the conventional methods based on the statistics are mainly used and show excellent results for the most part. The forecast algorithms for special days yield good results also but its forecast error is relatively high than the results of the weekdays and the weekends forecast methods. For summer special light-load period, none of the previous studies have been performed ever before so if the conventional methods are applied to this period, forecasting errors of the conventional methods are considerably high. Therefore, short-term load forecast for summer special light-load period have mainly relied on the experience of power system operation experts. In this study, the trends of load profiles during summer special light-load period are classified into three patterns and new forecast algorithms for each pattern are suggested. The proposed method was tested with the last ten years' summer special light-load periods. The simulation results show the excellent average forecast error near 2%.

• Journal of Astronomy and Space Sciences
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• 제35권2호
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• pp.83-92
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• 2018

The summer polar lower thermosphere (90-100 km) has an interesting connection to meteors, adjacent to the mesopause region attaining the lowest temperature in summer. Meteors supply condensation nuclei for charged ice particles causing polar mesospheric summer echoes (PMSE). We report the observation of meteor trail with nearly horizontal transit at high speed (20-50 km/s), and at last with re-enhanced echo power followed by diffusive echoes. Changes in phase difference between radar receivers aligned in meridional and zonal directions are used to determine variations in horizontal displacements and speeds with respect to time by taking advantage of radar interferometric analysis. The actual transit of echo target is observed along the straight pathway vertically and horizontally extended as much as a distance of at least 24 km and at most 29 km. The meteor trail initially has a signature similar to 'head echoes', with travel speeds from 20 - 50 km/s. It subsequently transforms into a different type of echo target including specular echo and then finally the power reenhanced. The reenhancement of echo power is followed by fume-like diffusive echoes, indicating sudden release of plasma as like explosive process probably involved. We discuss a possible role of meteor-triggered secondary plasma trail, such as fireball embedded with electrical discharge that continuously varies the power and transit speed.

• 한국컴퓨터정보학회논문지
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• 제29권11호
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• pp.31-40
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• 2024

높은 기온으로 인해 냉방부하가 상승하는 하절기의 낮에는 시간당 전력 수요가 증가하고 밤에는 낮에 비해 상대적으로 전력수요가 적은 특징을 보인다. 이러한 특징은 하계 전력 수요 예측에 있어 중요한 정보로 간주한다. 그러나 시간 정보를 단순히 더미변수로 표현할 경우, 모델은 시간의 변화를 학습하기보다는 단순히 시간대 간의 차이를 인식하는 데 그치게 된다. 본 연구에서는 이러한 문제를 해결하기 위해 푸리에 변환을 활용하여 시간 변수를 사용한 방식으로 접근하고자 한다. 푸리에 변환을 이용한 시간 변수는 시간 간의 차이를 효과적으로 학습할 수 있을 것이다. BiGRU 모델을 사용하여 2022년과 2023년의 하계 전력 수요예측에 시간 변수의 형식에 따른 평가를 수행한 결과 푸리에 변환을 사용한 시간 변수를 사용한 모델이 MAPE 2.01%, 2.04%로 가장 우수한 성능을 보이는 것을 확인하였다. 본 연구의 결과는 전력 사용량이 증가하는 하절기의 전력 사용량 예측 정확도를 높여, 대규모 정전 사태와 같은 문제를 방지할 수 있을 것으로 기대한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.427-428
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• 2007

'07년 하절기 최대부하시 전력계통을 대상으로 고장계산, 조류분석 및 안정도 해석을 통한 계통운영상의 문제점을 분석하고 이에 대한 대책을 수립 시행함으로써 계통의 안정운영을 도모하고, 대학이나 연구소 등의 계통해석 업무에 도움을 주고자 한다.

• The Korean Journal of Ecology
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• 제14권4호
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• pp.469-479
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• 1991

The abundance and local distribution of birds around the three atomic power plants were studied during summer in 1998 and winter 1989. It was particularly pointed out how to determine species diversity indices, rarefaction model appeared and habitat use. During the study over 2,200 birds were censused; black-tailed gull, terek sandpipper, asian wandering tattler and australian curlew accountedfor over 76% of the observed birds in summer. Black-tailed gull, black-headed gull, mallard, ancient murrelet and tree sparrow accounted for 76% of the observed birds in winter. overall, 53 species were occurred ; 23 have been observed on yonggwang-gun, 16 used on ulchin-gun, 12 used on kyungju-gun in summer. 18 on yonggwang-gun,,14 on ulchin-gun,12 on kyungju-gun in winter respectively. These three habitats in terms of their of species richness were computed as follows; yonggwang-gun has the highest richness with an expected species number of 17.5 as the same as two season. Kyungju-gun has the lowest with an expected species number of 8.2 in summer and 11.5 in winter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.85-86
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• 2006

'06년 하절기 최대부하시 전력계통을 대상으로 고장계산, 조류분석 및 안정도 해석을 통한 계통운영상의 문제점을 분석하고 이에 대한 대책을 수립 시행함으로써 계통의 안정운영을 도모하고, 대학이나 연구소 등의 계통해석 업무에 도움을 주고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.282-283
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• 2008

'08년 하절기 최대부하시 전력계통 환경에서 고장계산, 조류분석 및 안정도 해석을 통한 계통운영상의 문제점을 분석하고 이에 대한 대책을 수립.시행함으로써 계통의 안정운영을 도모하고, 대학이나 연구소 등의 계통해석 업무에 도움을 주고자 한다.