The Research on the Distribution Network Reconfiguration and the Application of Immune Particle Swarm Optimization

Zucheng Huang,Lixia Chen,Wei Chen,Xiaojun Chen 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.11

With the rapid development of national economy, the demand for electricity is more intense. There is a new demand for the security, reliability and applicability of the power distribution system. The power distribution system is an important component of power systems. It plays an important role in connecting power production and users. Now the most important problem is nonlinear combinatorial optimization in large-scale mixed lines and how to reconfigure the distribution network. However, by deeply analyzing and studying immune particle swarm optimization, the mathematical model of distribution network reconfiguration is established. By coding the characteristics of closed-loop design and open-loop operation, it aims to reduce the consumption of network, balance the grid load, eliminate the current overload and achieve the ultimate goal of improving the power supply reliability.

역최적화를 활용한 물류거점 통합 유도

유건식 ( Geonsik Yu ),정예림 ( Yerim Chung ),박선주 ( Sunju Park ) 한국로지스틱스학회 2016 로지스틱스연구 Vol.24 No.3

본 연구는 업체 간 공동 물류화를 유도함으로써, 복잡해진 물류 구조를 조율하여 이로 인한 부정적인 외부효과를 줄이려는 정부 정책의 효율성을 높이기 위한 연결망 모형을 제시하고, 역최적화 알고리즘을 적용하여 탐색한 해를 어떻게 해석하고 활용할지에 대한 예시를 보였다. 특히 기존에 역최적화 알고리즘이 적극적으로 적용된 바 없는 정책 의사결정 분야에 방법론을 적용하여 다수의 의사결정자가 연관된 정책 설계에 수리적인 최적화를 도입할 수 있음을 보였다. 선행 물류 연구들에 의해 공동 물류화의 효과성과 활용 방안에 대한 심도있는 고찰이 이루어졌기 때문에, 본 연구는 역최적화 수리모형을 활용하여 공동 물류화 문제를 효율적으로 정책화하기 위한 모형과 계량적인 해법을 제시하는 데에 초점을 두었다. 연구의 목적을 위해 기존에 알려진 물류 대안을 개별 업체가 당면한 의사결정 대상으로 가정하고 시장 상황을 모형화하였다. 개별 업체가 갖는 물류 대안은 자사 물류 거점을 사용하는 것과 더불어, 공동 물류화와 리스등을 포함하는 것을 가정하였다. 해당 모형은 조합 최적화 이론에서 고안한 연결망 모형을 응용하였으며, 해당연결망의 접점은 기업의 의사결정 대안을 표현하도록 하고 접점 간의 연결에는 해당 대안에 관련된 비용을 할당하였다. 구성한 연결망 모형에 대해서 기존의 해법을 사용하여 정책 구성에 활용 가능한 비용 조정값을 도출할 수 있음을 보였다. 이 때 연결의 조정값이 양수일 경우, 이를 해당 경제 행위에 대한 과세 등으로 해석할 수있으며, 반대로 음수일 경우에는 보조금 지급 등으로 해석할 수 있다. 도출한 해로부터 발생 가능한 다양한 경우에 해의 특성에 대한 분석을 수행했으며, 추가적으로 이를 현실적인 제약 조건을 고려한 정책 상황에 어떻게 적용할 수 있을지에 대해 논했다. 이는 과세할 수 없는 행위 혹은 정책적 지원을 할 수 없는 행위가 고려될 경우에 어떻게 모형을 수정하여야 하는지에 대한 답이 될 수 있다. 본 연구는 역최적화라는 수리적 기법이 의사결정 및 정책 관련 분야에도 실용적으로 적용될 수 있음을 보였다. 특히, 우리가 제시한 방법은 최소한의 예산으로 시장에 효율적인 개입을 수행할 수 있는 방향을 도출함으로써 여러 의사결정자가 존재하는 공동 물류화유도 상황을 수리적으로 해결한다. 나아가, 본 연구가 제시한 모형은 공동 물류화 상황이 아니더라도 그 외 정부의 개입으로 시장을 조율하고자 하는 다양한 정책 문제나 3자에 의한 조율이 필요한 다른 문제에도 역최적화가 수리적인 해법이 될 수 있음을 보일 것으로 기대한다. This study suggests a network model that describes a product distribution service market with multiple decision makers or companies in order to minimize the negative externalities when inducing integrated distribution system. We apply the inverse optimization algorithm to the network model to minimize the cost of inducement policy and provide application examples for the methods we used. Different from preceding researches on distribution system integration issues that cover the practical usage and location selection for distribution centers, this paper focuses on suggesting a quantitative method for efficient policy design related to distribution market. To solve the problem, we suppose that each distribution company in the market can have several well­known alternatives for their distribution processes and formulate the whole decision making of the market with a network model. We assume that each company has following alternatives for their product distributions: utilizing their own distribution centers, leasing a warehouse from a competitor and using a joint distribution center with a competitor. Applying the network theory and the combinatorial optimization theory, we describe in the network model the companies and their decision alternatives as nodes and assign the cost of their decisions to the related link. By using the inverse optimization algorithm, we compute the optimal solution that can be applied to the policy making for distribution center integration by means of fine­tuning the distribution industry or the monetary inducement on joint distribution center. When the value of the given solution is positive, we can interpret it as additional taxation on a certain economic decision. On the other hand, if the value is negative, we can interpret the result as government subsidies. We analyze the characteristics of our optimization solution for different possible situations and consider practical constraints of formulating efficient inducement policy. By extending our linear programming model, we also show that our model can handle and optimize the market situations containing upper bounds or lower bounds of cost modifications. For example, situation including a limited amount of subsidies, taxation not allowed and etc. The mathematical method we proposed in this research can be used to design an efficient inducement policy for distribution system integration with minimum budget. And furthermore, our method can also be applied to other policy-related problems including market adjustment concepts.

Power Flow Algorithm for Weakly Meshed Distribution Network with Distributed Generation Based on Loop-analysis in Different Load Models

Hongsheng Su,Zezhong Zhang 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

As distributed generation (DG) is connected to grid, there is new node-type occurring in distribution network. An efficient algorithm is proposed in this paper to calculate power flow for weakly meshed distribution network with DGs in different load models. The algorithm respectively establishes mathematical models focusing on the wind power, photovoltaic cell, fuel cell, and gas turbine, wherein the different DGs are respectively equivalent to PQ, PI, PQ (V) and PV node-type. When dealing with PV node, the algorithm adopts reactive power compensation device to correct power, and the reactive power allocation principle is proposed to determine reactive power initial value to improve convergence of the algorithm. In addition, when dealing with the weakly meshed network, the proposed algorithm, which builds path matrix based on loop-analysis and establishes incident matrix of node voltage and injection current, possesses good convergence and strong ability to process the loops. The simulation results in IEEE33 and PG&G69 node distribution networks show that with increase of the number of loops, the algorithm’s iteration times will decrease, and its convergence performance is stronger. Clearly, it can be effectively used to solve the problem of power flow calculation for weakly meshed distribution network containing different DGs.

Distribution Network Data-Monitoring System based on Wireless Sensor Networks

Shihai Ma,Yan Zhao,Haiyan Zhang 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.3

Combining with the requirements of the development of the smart grid, we raised the research of distribution network monitoring system based on wireless sensor networks. In analysis of the status quo and deficiencies of the existing cable communication system of the distribution network, combining with the structure and characteristics of the wireless sensor networks, we built a new construction strategy of distribution network data monitoring system and discussed it in details regarding both the overall structure itself and the key technologies involved.

Reliability Assessment of Distribution Network Considering Mobile Energy Storage Vehicles and Dynamic Zonal Coupling

Yang Wei,Wang Dan,Guo Jingming,Zhang Yijiao,Zhang Jiajia,Bian Zhaoyuan 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.1

Mobile energy storage spatially and temporally transports electric energy and has fexible dispatching, and it has the potential to improve the reliability of distribution networks. In this paper, we studied the reliability assessment of the distribution network with power exchange from mobile energy storage units, considering the coupling diferences among diferent time and zones of the vehicle–road–network system. First, we constructed a basic mobile energy storage operation framework that supports the distribution network reliability. Next, we proposed a quantitative model to describe the dynamic zonal coupled vehicle–road–network system. Based on this model, the corresponding charging and discharging scheduling strategies for diferent mobile energy storage units are well designed to improve the efciency of power support. Then, we provided a distribution network reliability assessment algorithm handling the power exchange from mobile energy storage units. Finally, we used the IEEE 33-node example system to clarify the necessity of the vehicle–road–network model in accounting for dynamic zonal coupling. We also analyzed the impact of diferent characteristics of mobile energy storage on the reliability of the distribution network, and verifed that one can improve the distribution network reliability by increasing the response speed, power capacity, or charging/discharging power of mobile energy storage vehicles.

인터넷 종합쇼핑몰에서 상품네트워크의 구조적 특성과 매출성과 간의 상관관계 분석

정석봉 한국경영교육학회 2015 경영교육연구 Vol.30 No.3

Recently, researches about applying social network analysis to marketing have been increased. The previous researches have focused on designing networks based on customer’s purchase behaviors and making analysis schemes for marketing purposes. In this study, we tried to investigate the relationship between results of social network analysis and sales performance of a company. To this end, we designed product networks based on customer’s purchase behaviors in a certain internet shopping mall and interpreted the meaning of structure attributes of product networks at network levels. And we conducted a multiple regression analysis between the attributes and sales performances of the mall. Additionally, we designed two kinds of product networks according to the type of networks, binary and weighted network, and confirmed which type of network is more suitable to explain sales performance. As a results, we found that degree and strength of a product network is distributed according to a power law like general social networks. Also, it was confirmed that the more kinds of product being traded, the higher scope and strength on linked products at network levels, the lower the inclusiveness, the lower the tendency of monopolization has a greater positive impact on sales performance of the mall. In addition, we found that weighted networks have better explanatory power to the sales performance of internet shopping mall than binary networks. 최근 사회네트워크분석을 기업의 마케팅 활동에 활용하고자 하는 연구가 증가하고 있다. 이러한 연구들은 주로 고객의 구매패턴을 기반으로 네트워크를 구성하고 마케팅 활동을 위한 분석 기법을 개발하는데 초점을 두었다. 본 연구에서는 기업의 마케팅 활동을 위한 특정 분석기법 개발에 선행하여, 사회네트워크분석 결과와 기업의 판매성과 간의 상관관계를 규명하고자 한다. 이를 위하여 본 연구에서는 국내의 한 인터넷 종합쇼핑몰의 고객 구매내역 데이터를 기반으로 상품네트워크를 구성하고, 크기, 밀도, 포괄성 및 멱함수 지수 등 네트워크 수준의 구조적 특성이 상품네트워크에서 갖는 의미를 해석하며, 각 특성이 쇼핑몰의 매출성과에 미치는 영향을 다중회귀모형을 통해 분석하였다. 더불어, 네트워크의 모델링 방법에 따라 이진 및 가중 네트워크의 형태로 상품네트워크를 각각 구성하고 분석결과를 상호 비교함으로써 기업의 판매성과를 설명하는데 적합한 모델링 방법이 무엇인지 규명하였다. 분석결과, 인터넷 종합쇼핑몰의 상품네트워크는 일반적인 사회네트워크와 유사하게 연결정도 및 강도 측면에서 멱함수 분포를 갖는다는 것을 확인할 수 있었다. 또한 거래되는 상품의 종류가 많을수록, 네트워크 수준에서 연결구매의 범위 및 강도가 높을수록, 포괄성이 낮을수록, 그리고 연결구매의 독점화 경향이 낮을수록 매출성과에 긍정적인 영향을 미치는 것으로 확인되었다. 더불어 이진네트워크에 비해 정보의 손실이 적은 가중네트워크가 쇼핑몰의 매출 성과를 보다 잘 설명하고 있음을 밝혔다.

조선왕조 가계 인물 네트워크

김학용(Hak Yong Kim) 한국콘텐츠학회 2012 한국콘텐츠학회논문지 Vol.12 No.4

조선 역대 왕의 가계에 등장하는 인물로 구성된 네트워크를 구축하고 분석한 결과, 일반적인 사회 네트워크와 같은 척도 없는 네트워크를 보여주고 있다. 조선왕조 가계 인물 네트워크가 비록 척도 없는 네트워크이지만 네트워크의 지름이 다른 사회 네트워크에 비해 비교적 큰데, 왕조 가계 인물 네트워크는 한 왕에서 다음 왕으로 이어지는 연속적인 특성이 반영된 것이다. K-코어 알고리즘을 도입하여 복잡한 네트워크를 단순화시킬 경우, 복잡한 네트워크에서는 발견하지 못하는 숨겨진 정보를 얻을 수 있는데, 왕조 가계 네트워크에서는 특별한 정보를 얻지 못하였다. 비교적 네트워크의 지름이 크고 길게 이어지는 네트워크에는 k-코어 알고리즘이 적합하지 못함을 의미한다. 단순한 네트워크 구축을 위해 가계 인물 네트워크를 구성하고 있는 소단위 네트워크 즉, 황후, 후궁, 공주나 옹주, 대군이나 군 중심의 네트워크를 구축하여 단순화시키고 그로부터 유용한 정보를 얻고자 하였다. 본 연구에서 복잡한 네트워크의 경우, 데이터베이스에서 분류 가능한 소단위 네트워크를 구축하여 유용한 정보를 도출하는 것도 복잡한 네트워크를 단순화하여 유용한 정보를 도출하는 방법이 될 수 있음을 제시한다. 동시에 역사적인 사실의 정보를 네트워크 관점에서 얻을 수 있음을 본 연구는 제시하고 있다. Family member network of kings in Chosun dynasty shows scale free network properties as if most social networks do. One of distinct topological properties of the network is relatively high diameter that reflects dataset composed of the one generation continuously falling to next one. When k-core algorithm as a useful tool for obtaining a core network from the complex family member network was employed, it is possible to obtain hidden and valuable information from a complex network. Unfortunately, it is found that k-core algorithm is not useful tool for applying narrow and deep structural network. The family member network is composed of kings, queens, princes, and princesses. It is possible to separate sub-family members and to construct sub-family member networks such as queen-centered, prince-centered, and princess-centered networks. Sub-family member networks provide an useful and hidden information. These results provide new insight that is analyzed by network-based approaches for the family member of the kings in the Chosun dynasty.

고려시대 역(驛) 분포의 지역별 불균등성

정요근 ( Jeong Yo-keun ) 부경역사연구소 2009 지역과 역사 Vol.- No.24

Regional distribution difference was one of main distinctive features of Koryo postal station network. There was meaningful difference of postal station distribution between higher local administrative units such as five provinces or two border regions in the Koryo era, and moreover regional difference of postal station density was found in proportion to importance of each local administrative unit even in a same province. Regional distribution difference of postal stations was mostly based on difference of regional importance among various areas since the foundation of Koryo dynasty. Especially, postal station distribution density of some regions, such as west coastal area of Yanggwang, Sohae and Cholla province and Hapchu county of Kyongsang province and its sok-hyuns, was remarkably sparse compared with neighboring areas. It tells us that these areas’ regional importance and the level of development were not so high compared with other regions. But regional distribution of postal stations was significantly improved during the late Koryo and early Choson era. Eventually it became the late 15th century, and remarkable decrease of a postal station number happened in two border regions, while new establishment of postal station continued in west coastal region where regional distribution density of postal stations was sparse in the Koryo era. Therefore, formation of postal station network system in the early Choson era was reorganized in the direction of attaining improvement of regional distribution difference of Koryo postal station network system.

A Key Pre-distribution Scheme Based on Deployment Information

Shulan Xia,Jilin Wang,Ru-gang Wang 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.11

A scheme of grouping key distribution based on polynomial protocol is proposed and experimentally demonstrated. The grouping idea is ingeniously used in the design of key distribution. The performance is experimental demonstrated by comparing with kinds of random key pre-distribution schemes. The results show that it can not only guarantee the key connected rate but also strengthen the security performance of the network, and this scheme is very suitable for static underwater acoustic communications network.

Robust Optimization Dispatch Method for Distribution Network Considering Four-Quadrant Power Output of Energy Storage Devices

Li Yue,Xiao Xiao-Bing,He Xiao-Meng,Huang Bo-Yang,Fang Yang,He Xin-Yi 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.2

This paper describes a technique for improving distribution network dispatch by using the four-quadrant power output of distributed energy storage systems to address voltage deviation and grid loss problems resulting from the large integration of distributed generation into the distribution network. The approach creates an optimization dispatch model for an active distribution network. The objective function aims to minimize power purchase costs, network loss costs, and voltage deviation penalties. In addition, the method employs an interval robust optimization technique to handle uncertainties related to solar turbine output and load demand. To solve the optimal power fow problem for AC in the distribution network, this paper implements the second-order cone relaxation technique to convert it into a solvable second-order cone programming problem. Moreover, the Big-M method is used to handle the nonlinear terms in the objective function. Finally, simulation experiments are conducted on the IEEE33 node system to verify the efectiveness and superiority of the proposed method. The simulation results indicate that the system's operating cost can be signifcantly reduced. Additionally, it has a positive impact on reducing voltage deviation and system loss, ultimately improving the operation of the distribution network system.