A Practical Voltage Error Correction Technique for Distribution System under Distribution Automation Environment

Muhammad Aslam,Hyung-Seung Kim,Myeon-Song Choi,Seung-Jae Lee 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

Transmission system has been well studied since long time and power system techniques of distribution system are more or less derived from transmission system. However, unlike transmission systems, many practical issues are encountered in the distribution system. Considerable amount of error is observed in voltage obtained from the Feeder Remote Terminal Units (FRTUs) measured by the pole mounted PTs along the distribution feeder. Load uncertainty is also an issue in distribution system. Further, penetration of Distributed Generators (DGs) creates voltage variations in the system. Hybrid radial/ loop distribution system also make it complicated to handle distribution system. How these constraints to be handled under Distribution Automation (DAS) environment in order to obtain error free voltage is described in this paper and therefore, a new approach of voltage error correction technique has been proposed. The proposed technique utilizes reliable data from substation and the FRTUs installed in DAS. The proposed technique adopts an iterative process for voltage error correction. It has been tested and proved accurate not only for conventional radial systems but also for loop distribution systems.

화훼도매 온라인 거래처리 시스템을 통한 유통경로 개선방안 연구: (주)플로마켓 사례

이승창,안성혁 한국유통과학회 2010 유통과학연구 Vol.8 No.1

The ICT(information & communication technology) led to a dramatic change of floral distribution service, a phase of competition between wholesales and retail stores, and distribution channels in floral industry. It was expected that a role of the intermediaries in this industry would have reduced due to the improvement of transaction process by ICT. However, the ICT made to overcome a regional limit of the floral retail distribution service leading to an increase in sales and enlargement of the stores. And even it made possible to bring out another type of intermediaries such as private associations. This case study focuses on what kinds of efforts the floral wholesale distributors have made to enable a distribution process more smoothly between the wholesale distributors and retail stores through the information system, and what the failure factors in adopting the information system have been. This paper is also to examine how the wholesale distributors have changed themselves to gain dominant positions in distribution channels. As a result of the study, it was found that the intermediaries mostly failed in successfully achieving the distribution channel innovation through the information system because of several main reasons. FLOMARKET Inc. tried to innovate a distribution channel to obtain high quality goods through consolidating a wholesale distribution market in that segregated both floral joint market from free markets. after implementing the information system with consideration of the failure factors, FLOMARKET Inc. was able to minimize goods in stock and make a major purchase of various goods. In addition, it made a possible pre-ordering process and an exact calculation of purchasing goods so they could provide their products with market price in real time, which helped for the company to gain credits from their customers. Also, FLOMARKET Inc. established the information system which well suited to its business stage in order to deal with a rapidly changing distribution environment. It's so obvious that the transaction processing system of FLOMARKET Inc. definitely helped to share information among traders more seamlessly and smoothly in realtime, standardize goods, and make a transaction process clearer. Besides, the transaction information helped the wholesale distributors and retail stores to make more strategic decisions in their business because through the system they enabled to gather the marketing intelligence information more easily and convenient. If we understand that the floral distribution market is characterized by the low IT- based industry, it's worth to examine a case study proving that the information system actually increases the productivity of the transaction process in the floral industry.

A Practical Voltage Error Correction Technique for Distribution System under Distribution Automation Environment

Aslam, Muhammad,Kim, Hyung-Seung,Choi, Myeon-Song,Lee, Seung-Jae The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

Transmission system has been well studied since long time and power system techniques of distribution system are more or less derived from transmission system. However, unlike transmission systems, many practical issues are encountered in the distribution system. Considerable amount of error is observed in voltage obtained from the Feeder Remote Terminal Units (FRTUs) measured by the pole mounted PTs along the distribution feeder. Load uncertainty is also an issue in distribution system. Further, penetration of Distributed Generators (DGs) creates voltage variations in the system. Hybrid radial/ loop distribution system also make it complicated to handle distribution system. How these constraints to be handled under Distribution Automation (DAS) environment in order to obtain error free voltage is described in this paper and therefore, a new approach of voltage error correction technique has been proposed. The proposed technique utilizes reliable data from substation and the FRTUs installed in DAS. The proposed technique adopts an iterative process for voltage error correction. It has been tested and proved accurate not only for conventional radial systems but also for loop distribution systems.

소매업의 유통정보시스템 구축 방안 연구

옥선종,이준우,김유오 한국유통정보학회 2000 유통정보학회지 Vol.3 No.2

The information-based age will emerge according to the advancement of the whole society, change from distribution revolution to distribution information revolution has a meaning to facilitate innovation. Such distribution revolution starting with a purpose to provide various goods and competitive price for customers when real mass production, consumption appeared, finally has got to cope with the age of great transition. Distribution of informationalization helps the effectiveness of the whole distribution system by creating information network using various information function, human resources at each stage from to manufacture industry based on customer information. This paper aims to check these conditions, attempt theoretical approaches through existing literature and precedent studies, review application cases currently introduced and enforced, and clarify the fundamental framework of distribution information system available at the distribution information system in our country using the cases of advanced distribution companies. Accordingly, it examined the basic system of bar code, POS and VAN/EDI to be basis in the construction of distribution information system, compared the construction plan through advanced distribution companies and reviewed its direction, furthermore investigated mainly its application system, SCM, ECR/QR and the direction of our country's distribution information system. The limitation of this paper lies with that correct verification in the introduction and utilization of enterprises' distribution system was not performed because it was carried out through consideration by literature. For the time to come, research will be continuously conducted taking into consideration the linkage of our country's distribution information system in growing stage with that of the advanced countries in stable stage.

분산전원을 포함하는 시스템 운용 플랫폼을 위한 송배전 통합 해석 하이브리드 알고리즘 개발

송종석(Chong-Suk Song),서재완(Jae-Wan Suh),장문종(Moon-Jong Jang),장길수(Gil-Soo Jang) 한국조명·전기설비학회 2013 조명·전기설비학회논문지 Vol.27 No.1

Owing to the increase in the penetration of distributed generation the DGs connected to the distribution system have an effect on the system conditions of the transmission system and neighboring distribution systems. This makes the separate analysis of the transmission and distribution system no longer valid and requires the consideration of both the system in the analysis process. This paper proposes a transmission/distribution integrated analysis hybrid algorithm that would ensure the accurate analysis of the system by reflecting the results of the transmission and distribution system analysis on each other. Different scenarios are being analysed in order to verify the effectiveness of the hybrid algorithm by observing the effects of the DG connected distribution system on the transmission system and neighboring distribution systems. The algorithm and simulations performed are being conducted by MATLAB and the IEEE 30 bus system and a test distribution system has been utilized for the transmission and distribution systems respectively.

태양광전원의 연계용량에 따른 ±35kV급 MVDC 실증배전망의 경제성평가 모델링

이민행,김지명,김경화,이예빈,김윤호,노대석 한국산학기술학회 2024 한국산학기술학회논문지 Vol.25 No.2

Recently, the demonstration projects on an MVDC distribution system have been actively carried out to apply ±35kV MVDC to the existing AC distribution system to overcome the grid connection delay issue of renewable energy sources in Korea. However, because the DC distribution system may be expected to be more expensive than AC distribution system due to the high cost equipments such as inverter, converter and DC breakers, a research is required on the introduction of MVDC distribution systems in terms of economic aspects. Therefore, this paper presents the introduction types of distribution system by scenario based on the capacity of PV system and the feeder length in the MVDC demonstration distribution system, and proposes an economic evaluation modeling to criteria the feasibility of MVDC distribution system. Where, the economic evaluation modeling is classified by cost and benefit factors. The cost factors consist of construction and operation costs of the AC and DC distribution systems. And also, the benefit factors are composed of power loss reduction in AC and DC distribution systems, and electrical pricing, REC pricing, carbon emission pricing based on the capacity of PV systems. From the simulation results based on the proposed economic evaluation modeling using CPI(cost performance index) and the present worth method, it is confirmed that hybrid AC/DC distribution system is the most economical and feasible regardless of the introduction capacity in PV system.

우리나라 농산품 물류 체계 현황 및 문제점 분석에 관한 연구

정진욱,박운호,이승호,조창현 국토지리학회 2016 국토지리학회지 Vol.50 No.2

Local distribution system has developed toward global scale along the development of transportation and information communication technology. This leads to increasing importance of national distribution policy. Domestic market of distribution has grown rapidly. The shortage of distribution infrastructure supply, inefficient management of distribution facilities and complex distribution system weaken by the competitiveness of distribution industry. The paper aims at comparatively analyzing the distribution systems of industrial and agricultural products. Agricultural products have, unlikely industrial products, various types of distribution systems including different paths through wholesale market, direct market and distribution companies. This environment makes it difficult to set the efficient distribution systems. To this end, the paper identifies the difference in distribution flow between industrial products and agricultural products, and analyzes the difference of distribution costs of each Origin-Destination distances and agricultural items. These investigations uncover the cause of the problems of domestic distribution systems regarding the inefficiency of agricultural distribution systems. The study provides the insight of the nature of the problem embedded in domestic distribution systems, in particular in the difference between industrial and agricultural products. 교통과 정보통신기술의 발전은 물류의 범위를 지역적에서 국가적으로 확장시켰으며, 이에 따라 국가 단위의 물류 정책에 중요성이 강조되고 있다. 하지만 국내 물류 시장의 급격한 성장은 물류 시설의 공급 부족과 비효율적 운영 등의 문제를 야기했다. 특히 농산품은 제품의 특성상 신선도 하락 등의 문제가 존재하며, 제조업 제품과 달리 도매시장, 직거래, 유통업체 등 다양한 경로의 물류 체계가 설정되어 있기 때문에, 물류 체계의 비효율의 부정적 영향이 가장 크게 발생할 수 있는 품목이다. 이에 본 연구는 제조업 제품을 포함한 전체적인 물류 체계와 농산품의 물류 체계를 비교 분석하였으며, 농산품의 운송 거리 및 세부 품목별 물류비의 차이를 사례분석을 통해 밝혔다. 분석 결과, 생산지-소비지의 거리보다는 농산물 세부 품목의 감모 등 따라 직거래로의 전환할 때의 비용 절감 효과가 더 나타났다. 본 연구는 향후 물류 체계 정립을 통한 효율화 방안에 연구를 위한 선행적인 연구의 성격을 갖는다.

A Study on Distribution System of Pharmaceuticals in the Korea

김판진,류충열,남궁석,전타식,윤명길 한국유통과학회 2008 유통과학연구 Vol.6 No.2

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.

직류기반 가변속 발전 시스템을 이용한 에너지 절감에 관한 연구

박기도,노길태,김경화,문창재,김종수 해양환경안전학회 2023 해양환경안전학회지 Vol.29 No.6

As international environmental regulations on ship emissions are gradually strengthened, interest in electric propulsion and hybrid propulsion ships is increasing, and various solutions are being developed and applied to these ships, especially stabilization of the power system and system efficiency. The direct current distribution system is being applied as a way to increase the power. In addition, verification and testing of safety and performance of marine DC distribution systems is required. As a result of establishing a DC distribution test bed, verifying the performance of the DC distribution (variable speed power generation) system, and analyzing fuel consumption, this study applied a variable speed power generation system that is applied to DC power distribution for ships, and converted the power output from the generator into a rectifier. A system was developed to convert direct current power to connect to the system and monitor and control these devices. Through tests using this DC distribution system, the maximum voltage was 751.5V and the minimum voltage was 731.4V, and the voltage fluctuation rate was 2.7%, confirming that the voltage is stably supplied within 3%, and a variable speed power generation system was installed according to load fluctuations. When applied, it was confirmed through testing that fuel consumption could be reduced by more than 20% depending on the section compared to the existing constant speed power generation system. 국제적인 선박 배출 가스에 대한 환경 규제가 점차 강화됨에 따라 전기추진 및 하이브리드 추진선박에 대한 관심이 증대되고 있으며, 이러한 선박에 적용하기 위한 다양한 솔루션이 개발 및 적용되고 있는데 특히 전력계통의 안정화, 시스템의 효율성을 높이기 위한 방안으로 직류배전시스템이 적용되고 있다. 또한, 선박용 직류배전시스템에 대한 안전 및 성능에 대한 검증 및 시험의 중요성이 요구되고 있다. 본 연구는 직류배전 테스트베드 구축 및 직류배전(가변속 발전)시스템에 대한 성능을 검증하고 연료소모량 분석한 결과로서 선박용 직류배전에 적용되고 있는 가변속 발전시스템을 적용하였으며, 발전기에서 출력되는 전력을 정류기를 통해 직류전력으로 변환하여 시스템에 연계하고 이러한 장치들을 감시 및 제어하기 위한 시스템을 개발하였다. 이러한 직류배전 시스템을 적용한 시험을 통해 최대 전압은 751.5V이고 최소전압은 731.4V가 계측되어 전압변동률은 2.7%로 3% 이내에서 안정적으로 전압이 공급되는 것을 확인하였고 부하변동에 따라 가변속 발전시스템을 적용하였을 경우 연료소모량이 기존 정속발전시스템과 비교하여 구간에 따라 최대 20%이상 연료절감이 되는 것을 시험을 통해 확인하였다.

명사십리권역 수산물 유통구조의 개선방안에 관한 연구

임용택 ( Yong Taik Lim ) 한국도서(섬)학회 2012 韓國島嶼硏究 Vol.24 No.2

Myungsasibri area`s main income sources are fishery(seaweed) products. This area has 4 villages, the Sinjimyeon`s Daipyeongri, Shinri, Naijungri, and Imchonri. In 2011, Myungsasibri`s invented income total was 81.26hundred million won, which included sea mustard 2.96, kelp 4.58, bundle of laver 69.9, abalone 2.8 and fish 1.07. Also, the distribution of this area`s fishery products shows a high ratio in non-system and market sales. Therefore there is a need to balance and redistribute the ratio by extending direct sales in order to improve the inefficient system. The analysis shows that this area`s failure in fishery products` distribution was caused by lack of understanding in distribution, absence of distribution information system, inefficient distribution structure by multistage distribution, supply bargaining power insufficiency, and insufficiency of distribution infra. Lack of distribution infra is known as the cause of price decline, for it restricts the processing and storage business. Therefore there is a need to introduce a new distribution system, a new shift from the old system. The new system should include sales channel`s construction for direct sales`s activation, a joint organization which can supply bargaining power strengthening, improvement of distribution infra, and also need to be open to farmers market and rural marketplace. In addition, sales network`s spread and organization capability should be strengthened by self sustainable effort. Also, support projects need to take place at the national level in fishery-producing areas.