• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.8
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• pp.1161-1167
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• 2015

Distribution Management System(DMS) ienhancing distribution automation system-based operation efficiency is an optimized system by various operational applications in a distribution network. DMS employs various applications like topology reconfiguration, volt/var control, and restoration at events such as overload, voltage violation, and a fault in a distribution system. An operation efficiency to employ multi-applications as restoration with short-term load forecasting is higher than a performance by a single application; and the applications are accomplished by an operator’s control. Applications’ combination is determined by various alarm information which means critical issues in order to operate a distribution system. Thus, this paper proposes an application management system which can configure application combination, control applications depending on alarm information and check their performance condition. The proposed application management system can be customized by operator easily and have high operation efficiency and reliability because it is worked by reviewed alarm information from operator.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.29-36
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• 2013

This paper deals with the analysis of the customer voltage characteristic in distribution system interconnected with large scale PV system. There would be many power quality issues which are caused by reverse power flow of PV system interconnected with distribution system. In order to analyze the effect of PV system on the customer voltage, detailed modeling method of distribution system and modified modelling method of PV system are proposed using PSCAD/EMTDC in this paper. So far, less than dozens KW of PV system can be simulated with the existing modelling method. Therefore, a new modeling method which can simulate the large scale PV system is proposed by considering the relationship equation on the phase and voltage in the current control algorithm. From the simulation result of proposed modelling method, it is confirmed that an optimal operation method in distribution system is suggested by analyzing the effect of PV system on customer voltage.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1776-1786
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• 2010

Intelligent distribution automation system have total monitoring and control capability. The system covers substation, distribution network, distributed generations and customers at HV system. Various intelligent distribution facilities installed at distribution systems have voltage sensor, current sensor, aging monitoring sensor. Intelligent Feeder Remote Terminal Unit (IFRTU) tied to intelligent distribution facilities process information from facilities and it checks information of fault, power quality and aging of distribution facilities. The information is transmitted to master station through communication line. The master station have remote monitoring system covers substation, distribution network, distributed generations and customers. It also have various application programs that maintain optimal network operation by using information from on-site devices.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.6
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• pp.523-529
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• 2020

Power distribution management system is essential for the efficient management and operation of power distribution networks. The power distribution system is a system that manages the distribution network based on IT, and has been evolving along with the development of the power industry. The current power distribution system is designed to operate at a relatively low network transmission speed based on the independent operation of the main equipment. However, due to distributed resources such as photovoltaic or energy storage devices, which are rapidly increasing in popularity in recent years, the operation of future distribution environments is becoming more complex, and various information needs to be collected in real time. In this study, the requirements of the next-generation power distribution system were derived to overcome the limitations of the existing power distribution system, and based on this, the communication network system and performance requirements for the distribution system were defined. In order to verify the performance of the designed system, a software-based terminal device simulator was developed because it takes excessive time and cost to introduce a large-scale system such as a power distribution system. Using the simulator, a test environment similar to the actual operation was established, and the number of terminal devices was increased up to 1,000. The proposed system was shown to satisfy the requirements to support the functions of the next-generation power distribution system, recording less than 10 % of the communication network bandwidth.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1199-1208
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• 2013

In recent years, the development of application programs for distribution system analysis and control has been essential part for distribution management system (DMS). In this paper, we propose the common database for application programs of distribution management system. The proposed database model has several characteristics as followings. First, the proposed database model is designed for the common use of almost the whole distribution application software. The static equipment model and dynamic type tables are mixed and the parallel table structure is applied. Second, the linked list structure of database are used for the fast processing of applications. The database model includes the hierarchy and non-hierarchy distribution system structure. Third, the reduction method of distribution database is applied. For this, we present the network reduction rules. The basic concept of reduction rules are the electrical unification of successive line section which has not lateral branches and the removal of simple lateral branches which has no devices and other laterals. Proposed database model is tested for the Jeju system of Korea Electric Power Corporation (KEPCO). Through the test, we verified that the proposed database structure can be effectively used to accomplish the distribution system operation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.4
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• pp.473-476
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• 2010

In this paper, we analyzed the short circuit current of a low voltage direct current distribution system. For the analysis, we performed the modeling of the low voltage direct current distribution system with a 6-pulse three-phase thyristor rectifier using the PSCAD/EMTDC, surveyed impedance of sources, transformers and distribution lines to run a simulation. A result of the simulation is that short circuit currents of the direct current distribution system with the rectifier decreased due to a thyristor-ON-resistance(Ron). But in case of the low thyristor-ON resistance, output fault current of the rectifier increased over three-phase short circuit current of an AC power system without a rectifier by regular ratio of the rectifier. Because the output fault current of the rectifier can increase over interrupting the capacity of circuit breakers, studying short circuit currents of a low voltage direct current distribution system with a rectifier is necessary for introducing the direct current distribution systems.

• International Journal of Reliability and Applications
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• v.10 no.1
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• pp.43-57
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• 2009

In this article, we study the reliability equivalence factor of a series system. The failure rates of the system components are functions of time t. we study two cases of non-constat failure rates (i) weibull distribution (ii) linear increasing failure rate distribution. There are two methods are used to improve the given system. Two types of reliability equivalence factors are discussed. Numerical examples are presented to interpret how one can utilize the obtained results.

• Journal of Distribution Science
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• v.6 no.2
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• pp.41-60
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• 2008

This study examined state of local pharmaceuticals industry and investigated distribution system. The study found out associated problems as well as improvements of distribution system of local pharmaceuticals. Finally, to improve distribution system of local pharmaceuticals, the study investigated distribution system of 10 kinds of pharmaceuticals of 'J' Company being a leading local manufacturer of local pharmaceuticals, and found out improvements of the distribution system. The study collected and compiled 'J' Company's internal slips and reporting material from April 1, 2008 to July 31, 2008, and interviewed persons in charge continuously to find out state and problems of the distribution system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.75-81
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• 2015

At the end of the 19th century, Edison's DC power system and Tesla's AC power system was debated in power market. Finally, AC system became the primary system of the power market because both step-up and step-down of voltage by using transformer and long-distance power transmission are easily possible. However, nowadays the power market takes some action for introducing DC system. Both domestic and foreign researchers are conducting the study on the DC system as well. Some researchers have conducted the studies on power quality and economic evaluation of the DC distribution system but DC distribution system is still controversial in terms of the effectiveness and reliability. In this paper, we calculate the reliability indices of the Low Voltage Direct Current(LVDC) distribution system considering arrangement of power electronics, layout of the distribution system, and distance between load points.

• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.23-45
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• 2012

The objective of this study is to provide development strategies in the production and distribution system of highland Chinese cabbage by evaluating and analyzing problems of the current system, focusing on several main stages between production and distribution system of highland Chinese cabbage. Through interview of groups such as farmers, distributers in the main producing areas, commission merchants of the wholesale market and large-scale distributors the relavant information was collected. Also, data such as production situations in main producing areas, distribution conditions in the wholesale market was analyzed. The functions of highland Chinese cabbage were classified and the current state of highland Chinese cabbage distribution system was investigated to provide an overall insight into the highland Chinese cabbage distribution system. Also the factors which will affect a price of wholesale market and consumer of highland Chinese cabbage were examined. Finally problems and improvements in the production and distribution system through analysis of the distribution system of highland Chinese cabbage were provided. the main contents of this study are as follows. The first is to keep stability of production in main producing areas by applying a differentiated production method, for example, rainshelter cultivation method. The second is to establish the distribution system which the relevant information is opened transparently. The third is that the consistent cold transportation system from main producing areas to consumers must be built.