• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2107-2114
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• 2009

It is impossible to take the instant action in the distribution system When fault occures in a substation because operation of the substation and the distribution system are separated. However the power system automation has been studying about unity operation and co-operation between SCADA and DAS(Distribution Automation System). In this paper proposes a new algorithm of efficiency restoration using a outage load switching to a healthy MTR a fault occurrence at a MTR in united system between DAS and SCADA. In addtion, proposed algorithm includes a outage restoration method which keeps MTR optimal capacity with reorganization of distribution network in case it can not restore outage state loads caused by shortage of healthy MTR remain capacity. In case that proposed sequence still can not complete restoration, this paper suggests a efficiency outage restoration with objective function included priority in outage loads. In the case studies, the proposed algorithm have been verified in 2 MTR and 3 MTR substation

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.660-668
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• 2007

In order to improve the efficiency of service restoration function in the current Distribution Automation System (DAS), in this paper it is proposed a more advanced and efficient service restoration approach using Multi-Agent technique based on distributed networks. In the current DAS, communication networks or protocol structures are centralized with communications between the central station and FRTU through 1:1 connection. In order to maintain the current systems and enhance the proposed Multi-Agent based service restoration scheme, a device of communication and intelligence, named MASX, is newly developed to make a FRTU as an agent to cooperate each others. the proposed system applied in a demo system for an distribution automation system and shows 8 times reduction of restoration time in restoration of blackouts.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.854-859
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• 2010

Distribution Automation System(DAS) is designed to improve operational efficiency by acquisition and control of remote data using its components such as central computation units, communication network and feeder remote terminal units. A conventional human machine interface of the DAS adopts a schematic diagram which is made by drawing power equipments on the geographic information system map. The single line diagram is more useful than the schematic diagram for the main tasks of distribution system operation such as protective relay coordination, service restoration and loss minimization. Since the configuration of the distribution line is changed according to the relocation of the open tie switches, the auto-drawing algorithm based on the connection between the sections and the switches is an essential technique. This paper proposes a new auto-drawing algorithm for a single line diagram of distribution systems based on tertiary tree and collision avoidance method. The feasibility of the proposed algorithm has been testified for various cases using practical distribution system with 12 feeders.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.558-560
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• 1997

In recent years, it becomes a worldwide trend that the power utilities focus their attention to the automation of their power plants and distribution systems, employing recent developed communication technologies. Following this trend, KEPCO has installed optical communication links along its power distribution lines and at the same time, has exhausted much efforts to implement its own Distribution Automation Systems(DAS) in possible early date. This paper presents some of initial design efforts toward KEPCO's DAS at KEPRI.

• Journal of Internet Computing and Services
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• v.5 no.4
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• pp.63-76
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• 2004

For efficient design and operation of a communication network, precise simulation of network characteristics is essential. This issue has been the focus of research by several groups. In this study, we first modeled the HTTP traffic which would be employed on simulation on the level of application using the real collected traffic data. There are two different viewpoints on the characteristics of web traffic pattern, Poisson distribution and self-similar characteristics. In our study, the results show that web traffic characteristics do not depend on only one type of distribution, but the traffic can be modeled as composition of these depending on the size of response of Web server. This implicates that the web traffic can be modeled as the combination of two characteristics. We also found that the characteristics of Web traffic rely on the properties of web servers. This result was deployed as a traffic generator in implementing the network simulator (NetDAS).

• Proceedings of the KIEE Conference
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• summer
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• pp.202-204
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• 2004

This paper presents a neural network technology for the detection and classification of the various types of power quality disturbances. Power quality phenomena are short-time problems and of many varieties. Particularly, the transients happen during very short durations to the nano- and microsecond. Thus, a method for detecting ·md classifying transient signals at the same time and in an automatic combines the properties of the wavelet transform and the advantages of neural networks. We test two neural network and compare the results of Backpropagation Neural (BPN) network with Radial basis function network (RBFN). RBFN is more useful to detect and classify than BPN. The configuration of the hardware of PQ-DAS and some case studies are described.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.472-473
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• 2006

배전계통 원격감시제어 기능을 수행하는 배전자동화 주장치 운영S/W는 정확한 개폐기 제어를 위해서 사용자에게 정보를 쉽고 빠르고 명확하게 전달해야 함을 기본으로 하고 있다 1998년 처음 도입된 소규모 배전자동화 시스템은 해가 거듭될수록 현장의 다양한 요구가 발생하게 되었고 이를 해소하고자 S/W 성능개선을 추진하게 되었다. 본 논문에서는 S/W개선내용을 GUI변경을 통한 편의성향상과 중요현황 및 통계화면 추가로 조작의 신뢰성향상, 조작 전 재확인절차 추가 및 데이터 손실방지 등의 안정성을 향상시켜 신속한 고장파악 및 정확한 고장복구로 안정된 전력공급에 기여할 수 있을 것으로 사료된다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2059-2064
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• 2007

This paper analyzed distribution network reliability related with the increment of outages and duration time according to distribution facilities increasing. KEPCO introduced distribution automation system in 1998 which could recognize outage section by remotely monitoring the fault current and reduce the blackout area by remotely controlling distribution switches. As the result of this outage time reduction using distribution automation system, the minimum distribution automation rate was fined out in this paper on the base of analyzing diverse data and how many switches were used in distribution system to improve distribution network reliability at the situation of distribution facilities increasing. This result can be used as the model that an overseas utility company applies distribution automation system in the future.

• Proceedings of the IEEK Conference
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• summer
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• pp.159-164
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• 2004

This paper aims towards designing and implementation of a new adaptive Peer to Peer (P2P) network that cluster itself on the basis of semantic proximity. We also developed an algorithm to classify the nodes to form the semantic groups and to direct the queries to appropriate groups without any human intervention. This is done using Bloom filters to summarise keywords of the documents shared by a peer. The queries are directed towards the appropriate clusters instead of flooding them. The proposed topology supports a system for maintaining a global, omnipresent trust value for each peer in an efficient manner both in terms of decision time and network load.

• Steel and Composite Structures
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• v.46 no.3
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• pp.319-334
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• 2023

Localizing damages is an essential task to monitor the health of the structures since they may not be able to operate anymore. Among the damage detection techniques, non-destructive methods are considerably more preferred than destructive methods since damage can be located without affecting the structural integrity. However, these methods have several drawbacks in terms of detecting abilities, time consumption, cost, and hardware or software requirements. Employing artificial intelligence techniques could overcome such issues and could provide a powerful damage detection model if the technique is utilized correctly. In this study, the crack localization in flat and folded plate structures has been conducted by employing a Backpropagated Artificial Neural Network (BPANN). For this purpose, cracks with 18 different dimensions in thin, flat, and folded structures having 15⁰, 30⁰, 45⁰, and 60⁰ folding angle have been modeled and subjected to free vibration analysis by employing the Classical Plate Theory with Finite Element Method. A Four-nodded quadrilateral element having six degrees of freedom has been considered to represent those structures mathematically. The first ten natural frequencies have been obtained regarding healthy and cracked structures. To localize the crack, the ratios of the frequencies of the cracked flat and folded structures to those of healthy ones have been taken into account. Those ratios have been given to BPANN as the input variables, while the crack locations have been considered as the output variables. A total of 500 crack locations have been regarded within the dataset obtained from the results of the free vibration analysis. To build the best intelligent model, a feature search has been conducted for BAPNN regarding activation function, the number of hidden layers, and the number of hidden neurons. Regarding the analysis results, it is concluded that the BPANN is able to localize the cracks with an average accuracy of 95.12%.