• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.10
• /
• pp.49-57
• /
• 2010

In order to provide electricity to users economically and safely, distribution automation systems (DASs) monitor and operate components of distribution systems remotely through communication networks. The fiber optic communication network has been mainly installed for the DAS of Korea Electric Power Corporation (KEPCO) because of its huge bandwidth and dielectric noise immunity. However, the fiber optic communication network has some shortcomings that its installation cost and communication fee are expensive. This paper proposes a complex network where WLANs are combined with conventional fiber optic communication networks in order to expand DAS easily and inexpensively. A fixed wireless bridge communication unit (FWB-CU) for the proposed complex network is implemented using IEEE 802.11a WLAN technology. The proposed complex network is built actually to verify its feasibility experimentally as a DAS communication network.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.11
• /
• pp.1330-1336
• /
• 2019

As the Fourth Industrial Revolution era began, a variety of devices are running on the cloud. These various devices continue to generate various types of data or large amounts of multimedia data. To handle this situation, a large amount of storage is required, and big data technology is required to process stored data and obtain accurate information. NAS (Network Attached Storage) or SAN (Storage Area Network) technology is typically used to build high-speed, high-capacity storage in a network-based environment. In this paper, we propose a method to construct a mass storage device using Network-DAS which is an extension technology of DAS (Direct Attached Storage). Benchmark experiments were performed to verify the scalability of the storage system with 76 HDD. Experimental results show that the proposed high performance mass storage system is scalable and reliable.

• Proceedings of the KIEE Conference
• /
• 1998.07g
• /
• pp.2399-2401
• /
• 1998

For a medium/small scale DAS, which using the PCS network as the system communication network, we developed the scheme of communication protocol of DAS between master and remote terminal. This paper presents advanced protocol which has basic frame format and data flow for the medium/small scale DAS, and the procedure of the developing sequence.

• Proceedings of the KIEE Conference
• /
• 1999.07g
• /
• pp.3015-3017
• /
• 1999

KEPCO is faced with a number of network choice for Distribution Automation System(DAS), such as Power Line, Pair. Coaxial and Optical Cable, etc. The increasing use of DAS requires suitable communication networks. KEPCO has exhausted much efforts to implement its own standard DAS in possible early date. This paper presents the DAS in KEPCO and some of initial design efforts toward KEPCO's DAS at KEPRI.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.9
• /
• pp.81-86
• /
• 2007

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.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.420_421
• /
• 2009

The digital TRS(Trunked Radio System) is an excellent alternative for the transmission medium for the DAS(Distribution Automation System). KEPCO(Korea Electric Power Corporation) made the power IT network with digital TRS system. The main function of the radio network is transmitting and receiving information for the DAS. KEPCO's digital TRS is based on TETRA standard. The digital TRS supports data communication for the electric power control and monitoring systems in various ways.

• ETRI Journal
• /
• v.30 no.5
• /
• pp.674-684
• /
• 2008

This paper proposes a dual addressing scheme (DAS) for IPv6 over IEEE 802.15.4 wireless sensor networks (WSN). DAS combines a global unicast address to cope with association link changes and node mobility, and it links local addresses to lighten the overhead of the system to save energy and resources. This paper describes DAS address formats, address autoconfiguration, and address translation tables in the gateway. A detailed description of DAS is provided through examples. Simulations are performed to demonstrate the performance improvements of the DAS compared with the IPv6-based WSN, which uses the conventional single address.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.4
• /
• pp.687-693
• /
• 2011

In this paper, problems and solutions are proposed for applying IEC 61850 to Distribution Automation System(DAS). Communication protocol integration in power automation system have issued by IEC standards, IEC 61850 of them has researched for applying IEC 61850 to many areas of power system in spite of that it was made for substation automation system. Especially, DAS is just about to apply IEC 61850 by communication network change from serial to ethernet although DNP 3.0 is used. But it's impossible to apply directly IEC 61850 to DAS by difference of environment which unfixed wide area and separated nodes in power distribution system unlike concept of IEC 61850 is made by Substation Automation System(SAS) environment of limited space. Thus, this paper proposed applications of three types which conceptual, practical, and future to consider problems and solutions when apply IEC 61850 to Ethernet based DAS.

• Publications of The Korean Astronomical Society
• /
• v.22 no.3
• /
• pp.63-73
• /
• 2007

In this paper, we introduce the performance test results of digital data processing system for KVN (Korean VLBI Network). The digital data processing system for KVN consists of DAS (Data Acquisition System) and high-speed recorder which called Mark5B system. DAS system performs the digitalization of analog radio signal through ADS-1000 gigabit sampler with 1 Gsps/2-bit and process the digital filtering of digital signal. Mark5B system records the output data of DFB (Digital Filter Bank) with about 1 Gbps. In this paper, we carried out the preliminary evaluation experiments of the KVN digital data processing system connected between DAS system and Mark5B with VSI (VLBI Standard Interface) interface which is designed for compatible in each VLBI system. We first performed all of the KVN digital data processing system connected by VSI interface in the world. In factory inspection phase, we found that the DAS system has a memory read/write error in DSM (Digital Spectrometer) by analyzing the recorded data in Mark5B system. We confirmed that the DSM memory error has been correctly solved by comparing DSM results with Mark5B results. The effectiveness of KVN digital data processing system has been verified through the preliminary experiments such as data transmission, recording with VSI interface connection and data analysis between DSM and Mark5B system. In future work, we will perform the real astronomical observation by using the KVN 21m radio telescopes so as to verify its stability and performance.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.5
• /
• pp.1034-1041
• /
• 2007

This paper presents the developing results of improved distribution automation system including system configuration and subsystem design, prototype hardware and software implementation, and pilot tests on the real distribution networks of Korea Electric Power Corporation (KEPCO). An integrated system is designed to combine independent system for the distribution field works with DAS; transformer monitoring, power quality monitoring, voltage monitoring, outage monitoring, etc. The communication network is hierarchically configured as main network and branch network and well-defined integrated terminal units were developed. In addition, useful host configuration and applications were developed to integrate the services with DAS or interfacing other systems. Pilot tests were performed to verify that the system enables to properly integrate the DAS and other services of the distribution network.