• Title/Summary/Keyword: Distribution system

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The Economic Design of the Multi-stage Distribution System Using Different Supplier according to Order Size (주문크기에 따라 다른 공급처를 이용하는 다단계 물류시스템의 경제적 설계)

  • 장석화
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.26 no.1
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    • pp.85-94
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    • 2003
  • In this paper, a mathematical model is developed for economic design of multi-stage distribution system that consists of factory, central distribution centers, local distribution centers and retailers. The retailers are supplied products from different stage suppliers according to order size. The retailers are supplied products from factory if demand amount is large, central distribution center if medium, local distribution center if small. The economic design is to determine the economic size of facility factors that consist of distribution system. The cost factors are transportation cost from supply places to demand places, handling cost at distribution centers and inventory holding cost at retailers. It is to determine the transportation route of each retailer, the size and number of the vehicle at factory and distribution centers, the handling amount at distribution centers in order to minimize the total costs. The mathematical model is represented, the solution procedure is developed, and a numerical example is shown.

Application of Rechlorination for Adequate Disinfection Ability in Water Distribution System (관로 내 적정소독능 확보를 위한 재염소 기법의 적용)

  • Lee, Doo-Jin;Kim, Young-Il;Lee, Jong-Min;Jung, Nam-Jung;Kim, Yong-Woon
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.5
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    • pp.701-707
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    • 2006
  • Disinfectant residual should be maintained to achieve biological stability during distribution of treated water. The wide distribution of retention times associated with storage and transport of water in a network and the reactivity of disinfectants make it difficult to maintain adequate residuals at critical locations. Rechlorination at some intermediate locations may reduce the total disinfectant dose while keeping residuals within specified limits throughout the water distribution system. In order to select the adequate location of rechlorination for achieving to maintain of residual chlorine throughout the distribution system, EPANET was used in this study. EPANET was well predicted chlorine transport and residual loss in the distribution system. Location of rechlorination was selected to maintain 0.4mg/L of residual chlorine throughout a water distribution system by field investigation and model simulation. The quantity of chlorine may reduced 36.7% and provided smooth residual between 0.42 and 0.60mg/L, when rechlorination would be used continuously at strategic location within the distribution system.

Electric power distribution system most suitable investment precedence decision aspect of the reliability side (신뢰도 측면에서 본 배전계통 최적투자 우선순위 결정)

  • Lee, Hee-Tae;Kim, Jae-Chul;Moon, Jong-Fil;Park, Hyun-Taek;Park, Chang-Ho;Park, Sang-Man
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.384-386
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    • 2003
  • Striking in change that present our country is much by electricity industry reform and the Korea Electric Power Corporation is deciding power distribution system reliability indices every year but power distribution system for reliability evaluation and establishment of investment program are consisting punily. If consider efficient inflection of resources and hereafter power distribution division that is limited for target achievement of schedule level service evaluation and reliability side in operation of the power distribution system, can expect efficient practical use of the power distribution property if gains in electrical side about these change and most suitable investment way consist because there is necessity of electric power plan establishment of area electric power distribution place of business unit. This paper consider proper reliability level and maximum effect through quantitative analysis to gain electrical gains of the power distribution system in reliability side depending on trend DB(Data Base) of data of electric power system composition appliance in this treatise and apply data administration and reliability rate analysis that serve to decide most suitable investment precedence to supply of electric power property to power distribution system present investment algorithm.

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Power Flow Calculation Method of DC Distribution Network for Actual Power System

  • Kim, Juyong;Cho, Jintae;Kim, Hongjoo;Cho, Youngpyo;Lee, Hansang
    • KEPCO Journal on Electric Power and Energy
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    • v.6 no.4
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    • pp.419-425
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    • 2020
  • DC distribution system has been evaluated as an excellent one in comparison with existing AC distribution network because it needs fewer power conversion stages and the full capacity of the equipment can be used without consideration for power factor. Recently, research and development on the implementation of DC distribution networks have been progressed globally based on the rapid advancement in power-electronics technology, and the technological developments from the viewpoint of infrastructure are also in progress. However, to configure a distribution network which is a distribution line for DC, more accurate and rapid introduction of analysis technology is needed for the monitoring, control and operation of the system, which ensure the system run flexible and efficiently. However, in case of a bipolar DC distribution network, there are two buses acting as slack buses, so the Jacobian matrix cannot be configured. Without solving this problem, DC distribution network cannot be operated when the network is unbalanced. Therefore, this paper presented a comprehensive method of analysis with consideration of operating elements which are directly connected between neutral electric potential caused by the unbalanced of load in DC distribution network with bipolar structure.

A Protective Scheme for Wind Farm Interconnected to Distribution System (풍력발전단지가 연계된 배전계통에서의 보호방안)

  • Kim, Kyoung-Ho;Lee, Jong-Beom;Seo, Je-Ho
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.478-480
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    • 2002
  • Wind energy can be conversed into electrical power using wind generator. Wind farm is made up of many wind generators, and it is often interconnected into distribution system to supply power for utilities. There are many protection problems on distribution system connected with Wind farm. It can effect on power quality severely when faults are occurred on distribution line or Wind farms. Therefore the correct protective scheme must be set for distribution system which has a Wind farm. In this paper, A wind farm connected into distribution line is simulated with several fault types which can be occurred on distribution line and Wind farm using PSCAD/EMTDC. And this paper proposes necessary relays to protect both sides of distribution system and wind farm.

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A Study on the Reliability Evaluation of Underground Distribution System (지중배전계통 공급방식의 공급신뢰도 평가 기법)

  • Choi, Sang-Bong;Kim, Dae-Kyeong;Jeong, Seong-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.7
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    • pp.309-317
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    • 2001
  • The objective of this study is to evaluate properly reliability of underground distribution system taking into account domestic circumstance. Interruption time and number of interruption customer by distribution system based on actual condition in domestic utility are considered as important index to estimate reliability of underground distribution system. This paper presents algorithm to evaluate reliability of underground distribution system by using a model system as new urban area. Evaluation results which is established are shown in detail according to whether automatic system is introduced or not.

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A Study on the Backorder Policies for Two-Echelon Distribution System (2계층 분배체계에서의 부재고 정책에 관한 연구)

  • Sohn, Kwon-lk;Yi, Jung-Min
    • Journal of Industrial Technology
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    • v.21 no.B
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    • pp.37-44
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    • 2001
  • Distribution System is considered as the most important part of SCM when the satisfaction of customer demand is considered. This paper focus on the backorder policies for stockout which is occurred in each regional distribution center of two-echelon distribution system facing stochastic demand process. Four concepts for the efficient system operation are suggested. First, at least 30% reduction of stockout is achieved by introduction of 50/25 allocation policy to distribution system. Second, transportation cost and lead-time of backorder are decreased by allowance of internal supply between regional distribution centers. Third, the frequency of emergency supply is minimized by application of Ship-up-to- expected-demand backorder policies. Finally we suggest several effective rules to select multi-internal suppliers. Simulation tests show the efficiency of our backorder policies and enhancement of customer service level.

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Reliability Evaluation of Power Distribution System Considering Maintenance Effects (유지보수 영향을 고려한 배전계통 신뢰도 평가)

  • Moon, Jong-Fil;Shon, Jin-Geun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.2
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    • pp.154-157
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    • 2010
  • In this paper, the Time-varying Failure Rates(TFR) of power distribution system components are extracted from the recorded failure data of KEPCO(Korea Electric Power Corporation) and the reliability of power distribution system is evaluated using Mean Failure Rate(MFR) and TFR. The TFR is approximated to bathtub curve using the exponential and Weibull distribution function. In addition, Kaplan-Meier estimation is applied to TFR extraction because of incomplete failure data of KEPCO. Also the reliability of the real power distribution system of Korea is evaluated using the MFR and TFR extracted from real failure data, respectively and the results of each case are compared with each other. As a result, it is proved that the reliability evaluation using the TFR is more realistic than MFR. In addition, it is presented that the application method at power distribution system maintenance and repair using the result of TFR.

A Study on the Development of the Minimization Algorithm of Total Operating Cost in a Multi-stage Distribution System by the Partial Delivery Method (분납조달 방법을 통한 다단계 분배시스템의 총운전비용 최소화 알고리즘 개발에 관한 연구)

  • 최진영
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.43
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    • pp.139-144
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    • 1997
  • The objective of this study is to establish an actual optimization strategy for the traditional multi-stage distribution system which consists of factory warehouse, central distribution warehouse, and regional distribution warehouse under the basic assumption of distribution system. A minimization algorithm of total operating cost in a multi-stage distribution system was developed by expanding the previously existing algorithm through consideration of additional transportation environment. Alternative non-linear transportation costs for the same travel distance can be applied for the multi-stage distribution system by estimating the corresponding characteristic values through the collection of the actual data representing the change of transportation circumstances.

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Characteristic Impedances in Low-Voltage Distribution Systems for Power Line Communication

  • Kim, Young-Sung;Kim, Jae-Chul
    • Journal of Electrical Engineering and Technology
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    • v.2 no.1
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    • pp.29-34
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    • 2007
  • The input and output impedances in a low voltage distribution system is one of the most important matters for power line communication because from the viewpoint of communication, the attenuation characteristic of the high frequency signals is greatly caused by impedance mismatch during sending and receiving. The frequency range is from 1MHz to 30MHz. Therefore, this paper investigates the input and output impedances in order to understand the characteristic of high frequency signals in the low voltage distribution system between a pole transformer and an end user. For power line communication, the model of Korea's low voltage distribution system is proposed in a residential area and then the low voltage distribution system is set up in a laboratory. In the low voltage distribution system, S parameters are measured by using a network analyzer. Finally, input and output impedances are calculated using S parameters.