객체지향형 실시간 EMS 데이터베이스 구축을 위한 개념디자인

최상열,김종형,신명철,김응모,김학만 성균관대학교 1997 학술회의지원논문목록집 Vol.1997 No.-

Currently, EMS(Energy Mangement System) database is implemented by relational concept but, It is hard to describe the characteristic of power system data which require real time management and composite type. This paper present the way how to design conceptual schema for EMS database using ovject-oriented concept which is free to decribe composite data type and support inheritance concept.

피더부하 균등화지수를 이용한 배전계통의 긴급정전복구 및 부하균등화

崔相烈,鄭澔聖,申明澈 성균관대학교 2003 학술회의지원논문목록집 Vol.2003 No.-

This paper presents an algorithm to obtain an approximate optimal solution for the service restoration and load balancing of large scale radial distribution system in a real-time operation environment. Since the problem is formulated as a combinatorial optimization problem, it is difficult to solve a large-scale combinatorial optimization problem accurately within the reasonable computation time. Therefore, in order to find an approximate optimal solution quickly, the authors proposed an algorithm which combines optimization technique called cyclic best-first search with heuristic based feeder loadings balance index for computational efficiency and robust performance. To demonstrate the validity of the proposed algorithm. numerical calculations are carried out the KEPCO's 108 bus distribution system.

최소자승법을 이용한 적응형 데이터 윈도우의 거리계전 알고리즘

鄭澔聖,崔相烈,申明澈 성균관대학교 2003 학술회의지원논문목록집 Vol.2003 No.-

This paper presents the rapid and accurate algorithm for fault detection and location estimation in the transmission line. This algorithm uses wavelet transform for fault detection and harmonics elimination and utilizes least square error method for fault impedance estimation. Wavelet transform decomposes fault signals into high frequence component D1 and low frequence component A3. The fomer is used for fault phase detection and fault types classification and the latter is used for harmonics elimination. After fault detection, an adaptive data window technique using LSE estimates fault impedance. It can find a optimal data window length and estimate fault impedance rapidly, because it changes the length according to the fault disturbance. To prove the performance of the algorithm, the authors test relaying signals obtained from EMTP simulation. Test results show that the proposed algorithm estimates fault location within a half cycle after fault irrelevant to fault types and various fault conditions.

The Development of Intelligent Direct Load Control System

Sang Yule Choi 한국인터넷방송통신학회 2015 Journal of Advanced Smart Convergence Vol.4 No.2

The electric utility has the responsibility of reducing the impact of peaks on electricity demand and related costs. Therefore, they have introduced Direct Load Control System (DLCS) to automate the external control of shedding customer load that it controls. Since the number of customer load participating in the DLC program are keep increasing, DLCS operators a re facing difficulty in monitoring and controlling customer load. The existing DLCS needs constant operator intervention, e.g., whenever the load is about to exceed a predefined amount, it needs operator’s intervention to control the on/off status of the load. Therefore, DLCS operators need the state-of-the-art DLCS, which can control automatically the on/off status of the customer load without intervention as much as possible. This paper presents an intelligent DLCS using the active database. The proposed DLCS is applying the active database to DLCS which can avoid operator’s intervention as much as possible. To demonstrate the validity of the proposed system, variable production rules and intelligent demand controller are presented.

Distribution Network Switching Automation Using Active Web Based Management

Sang-Yule Choi 한국조명·전기설비학회 2007 조명·전기설비학회논문지 Vol.21 No.9

Electric utility companies have the responsibility of providing good electricity for their customers. They have introduced the DA') (Distribution Automation System) to automate the power distribution networks. DAS engineers require state-of-the-art applications, such as a way to actively manage the distribution system and gain economic benefits from a flexible DAS architectural design. The existing DAS is not capable of handling these needs. It requires operator intervention whenever feeder overloading is detected while operator error could cause the feeder overload area to be extended. It also utilizes a closed architecture and it is therefore difficult to meet the system migration and future enhancement requirements. This paper represents a web based, platform-independent, flexible DAS architectural design and active database application. Recent advanced Internet technologies are fully utilized in this new DAS architecture allowing it to meet the system migration and future enhancement requirements. By using an active database, the DAS can minimize the feeder overloading area in the distribution system without operator intervention, thereby minimizing mistakes due to operator error.

Rediscovering Richard Wright as a S(p)ecular Border Intellectual

Sang Yule Kim 한국영미문화학회 2009 영미문화 Vol.9 No.2

This paper will rediscover the cultural legacy of Richard Wright as a `s(p)ecular border intellectual` in the age of globalization and it will examine how his legacy contributed to shaping contemporary transnational studies. Richard Wright makes a synthesis between class and race, between white and black, between Marxism and nationalism, between the individual and society. It is, therefore, necessary to rediscover Wright beyond his own racial and national boundary. Wright`s works should be newly understood as cultural texts that encode very diverse cultural influences of the 1930s-50s` American society and prepare ground for seed of the 21st century`s transnational studies. Wright gradually emerges as a border intellectual who observes race and colonialism from a global perspective. His s(p)ecular border position disrupts the clear-cut authority of domination because it disturbs the simple binary relationship between white and black, Western and non-Western. It makes him possibly modulate to his artistic advantage polarities such as modernism versus realism, fiction versus nonfiction, the personal versus the political, individual versus community, and race versus class. I believe this transnational approach of him will help Korean scholars and students experience a diverse cultural heritage of African American intellectual and give chance to have a transnational understanding of black culture.

Antioxidant Activity of Tannins Extracted from Agricultural By-products

Yuling Ding,Se-Young Jang,Hye-Jin Seong,Yujiao Tang,Eun-Kyung Kim,Eun-Kyung Kim,Byoung-Tae Jeon,Sang-Ho Moon 한국초지조사료학회 2016 한국초지조사료학회 학술대회논문집 Vol.2016 No.08

Distribution Network Switching Automation Using Active Web Based Management

Choi, Sang-Yule The Korean Institute of IIIuminating and Electrica 2007 조명·전기설비학회논문지 Vol.21 No.9

Electric utility companies have the responsibility of providing good electricity for their customers. They have introduced the DAS(Distribution Automation System) to automate the power distribution networks. DAS engineers require state-of-the-art applications, such as a way to actively manage the distribution system and gain economic benefits from a flexible DAS architectural design. The existing DAS is not capable of handling these needs. It requires operator intervention whenever feeder overloading is detected while operator error could cause the feeder overload area to be extended. It also utilizes a closed architecture and it is therefore difficult to meet the system migration and future enhancement requirements. This paper represents a web based, platform-independent, flexible DAS architectural design and active database application. Recent advanced Internet technologies are fully utilized in this new DAS architecture allowing it to meet the system migration and future enhancement requirements. By using an active database, the DAS can minimize the feeder overloading area in the distribution system without operator intervention, thereby minimizing mistakes due to operator error.

부너맨 주파수 추정 알고리듬을 이용한 풍력발전기 가변 전력신호 처리에 관한 연구

최상열(Sang-Yule Choi),이종주(Jong-Joo Lee) 한국조명·전기설비학회 2010 조명·전기설비학회논문지 Vol.24 No.12

On wind turbine generators, the speed and volume of the wind affect the turbine angle speed which finally determines the output level of the electric power. However it is very difficult to forecast correctly the future power output and quality based on previous fixed sampling methods. This paper proposes a variable sampling method based on Buneman frequency estimation algorithm to reflect the variations of the frequency and amplitude on wind power outputs. The proposed method is also verified through the performance test by comparing with the results from previous fixed sampling methods and the real measurement data.

데이터마이닝을 이용한 단기부하예측

최상열(Sang-Yule Choi),김형중(Hyoung-Joong Kim) 한국조명·전기설비학회 2007 조명·전기설비학회논문지 Vol.21 No.10

본 연구에서는 데이터 마이닝 기법을 이용하여 전력계통의 단기 부하 예측을 하는 방안을 제시한다. 기존의 단기부하 예측은 시계열 분석 방법이 주를 이루었으며, 이러한 방법은 방대한 양의 자료를 기반으로 데이터베이스를 만들고 이를 이용하여 여러 가지 계수를 이용하여 수요를 예측함으로써 많은 시간과 노력이 소요되고 있다. 따라서 본 연구에서는 좀 더 적은 시간과 노력으로 부하예측이 가능하도록 데이터마이닝 기법을 이용하여 요일별 그리고 특수 일의 패턴을 분석하고 의사결정트리를 이용한 예측방법을 제시하고자 한다. 그리고 현재 전력거래소를 통해 거래되고 있는 계통한계가격과의 관계를 분석하여 예측 계수에 계통한계가격을 추가하여 예측방법을 제시하고자 한다. This paper proposes information technology based data mining to forecast short term power demand A time-series analyses have been applied to power demand forecasting, but this method needs not only heavy computational calculation but also large amount of coefficient data. Therefore, it is hard to analyze data in fast way. To overcome time consuming process, the author take advantage of universally easily available information technology based data-mining technique to analyze patterns of days and special days(holidays, etc.). Ths technique consists of two steps, one is constructing decision tree, the other is estimating and forecasting power flow using decision tree analysis. To validate the efficiency, the author compares the estimated demand with real demand from the Korea Power Exchange.