Overview of Smart Distribution Grid

Smart grid has become the hot topic to domestic and foreign about the development trend of power grid in recent years, and communication technology is foundation of the development of smart grid; the paper forecasts the smart grid communications automation and development trend.Further from intelligent dispatching center, smart grid, smart distribution grid and users, in view of the existing and emerging intelligent and automatic application were communication needs analysis, and provide a reliable basis for the smart grid communications planning.

This paper introduces the concept of intelligent distribution network, development of smart grid technology with meaning and background as well as domestic and foreign research and development status of Smart Distribution Grid. It focuses on the advanced smart distribution grid distribution automation, self-healing distribution network control technology, AMI technology, the impact of distributed generation and micro-network after the access to the smart distribution grid, and construction of smart distribution network problems to be solved.

In real-time large-scale optimization problems, such as in smart grids, centralized algorithms may face difficulties in handling fast-varying system conditions, such as high variability of renewable-based distributed generators (DGs) and controllable loads (CLs). Further, centralized algorithms may encounter computation and communication bottlenecks while handling a large number of variables. To tackle these issues, consensus-based distributed strategies have been proposed recently. However, distributed computational intelligence (CI)-based techniques can provide a much better near-optimal solution within fewer iterations of the algorithm, which is a critical requirement in smart grids. Therefore, in this paper, a consensus-based dimension-distributed CI technique is proposed for real-time optimal control in smart distribution grids in which a large number of DGs and CLs are present. The proposed approach considers each DG or CL as a separate private entity, which is more relevant from the perspective of smart grid optimization. In the proposed consensus-based framework, each DG or CL is associated with an agent, and each agent is allowed to communicate only with its neighboring agents. The effectiveness of the proposed approach in terms of convergence, adaptability, and optimality with respect to a centralized algorithm and a benchmark algorithm is shown through simulations on 30-node and 119-node distribution test systems.

In the smart distribution grid, deep integration of power system and information system is the development direction. In order to effectively excavate the potential value of massive data generated in planning and operation phases, the storage of big data is one of the key technologies. This paper proposes a big data storage method for smart distribution grid based on neo4j graph database. Use the common information model (CIM) of power system for reference to establish topology model of smart distribution grid. The storage method of multivariate heterogeneous data is presented integrated the advantages of graph database and relational database. Simulation results on the IEEE standard test systems show that the proposed big data storage method is able to effectively improve data storage and analysis efficiency of smart distribution grid, and a practical citizen power grid is adopted to verified the effectiveness.

Competition in smart distribution grids

Strong and smart is the essential requirement of the development of modern power grid and the twenty-first Century energy development driving force. Smart grid bearing in response to changing in the environment, improving energy efficiency, reducing carbon emissions is an important mission. Smart grid has become the new development trend and new directions of the world power grid. The effective coordination of demands interest group of Smart Grid, promote the orderly development of smart grid. The main purpose is to realize Smart Grid interoperability and to guarantee open framework of Smart Grid. The IEC (International Electrical Commission), NIST (National Institute of Standards and Technology) and SGCC (STATE GRID Corporation of China) issued technology standards roadmap of Smart Grid. From technology view of Smart Grid, the IEC include 13 domains. From view of interest group of Smart Grid, according to the United States market conditions, the NIST covers 7 domains. The SGCC covers 8 domains, according to Chinese power industry conditions. The future five years and fifteen years of IEC, NIST and SGCC smart grid technology standard trend focuses are given, in the way of the mathematical model of probability distribution, according to the technology standard requirements of maturity of the Smart Grid related fields of technology, products and market. It is likelihood the middle and long-term development focuses of future Smart Grid technical standards that two-way interactive service of power consumption, distribution management, electric storage, renewable energy generation. It is suggested that the Smart Grid technology advantage into standard advantage, in the promotion of Smart Grid equipment R & D and manufacturing level and promote the overall construction of Smart Grid at the same time, to strengthen our country voice in the Smart Grid international standards, to seize commanding heights of technical innovation and industrial development.

Smart grid is an essential part of the world's changing energy landscape. The uptake of smart grid by utilities is however hampered by the perceived complexity and large capital investment required to implement resilient Information Communication Technology (ICT) and networks that can support self-healing smart grids. Furthermore, failure to meet stringent smart grid communication reliability requirements can have disastrous consequences for grid owners and users. Many of the challenges utilities face with their smart grid ICT network development plans can be attributed to a reliance on conventional designs centred on expanding network hardware infrastructure in vast grid networks. What is needed to overcome these challenges is alternative ways of designing smart grid communication networks, using software defined approaches. This paper proposes a framework that supports software defined designs by combining the principles of the Internet of Things (IoT) paradigm and Machine-to-Machine (M2M) communication. Using the frameworks of software defined systems and virtualisation, our proposed architecture aims to provide a more flexible and affordable approach to developing and maintaining grid communication networks while offering a high level of network reliability, required for various smart grid applications. An evaluation of the implementation of this architecture in a design, based on a real city distribution grid, shows that a software defined communication network is easy to implement when using virtual machines running on existing computer infrastructure and that it is capable of supporting the network functions required for improving communication reliability. We conclude that this approach can potentially promote the adoption of smart grid by utilities while offering new innovative ways for smart grid developers to improve their grid designs.

There are many kinds of characteristics of smart distribution grid, such as the complex structure, the complexity of the users, and the factors that affect the power grid loss, which not only related to the spatial distribution of the load, but also the load on the time scale of the power changes. Aiming at the relationship between the load and the network loss in the smart distribution grid, the relationship between the load and the network loss is taken into consideration, and the deep intrinsic relationship between the load and the loss is extracted and the corresponding temporal and spatial characteristic parameters are presented. Based on the spatial parameters and time parameters of the relationship between the equivalent load and the network loss, a time-space characteristic analysis model of equivalent load is established. Based on the data of a regional distribution network in Jiangsu Province, the correlation between the equivalent load and the network loss is analyzed, and its feasibility is verified. And to analyze its correlation to explore the deep link between load and loss.

Evaluation of potential benefits is the key issue to set up suitable business model and pricing strategy for demand response. In view of the severe energy and environmental issues, low carbon development is inevitable as well. In this paper a demonstration project of smart distribution grid in Jiangxi province in China is introduced. The mechanism of demand response in this demonstration project is analyzed. Then a framework is proposed to identify the corresponding potential low-carbon effects of smart distribution network and a specific evaluation method has been established to quantify the total low-carbon effects of smart distribution grid. Moreover a simulation platform to evaluate the carbon dioxide emission of smart distribution grid is designed. It is expected that, possible demand response solutions and potential low-carbon effects could be analyzed accordingly based on this platform.

Locational signals to reduce network investments in smart distribution grids: What works and what not?

With the rapid development of national economy, our demand for power resources has also increased rapidly. The traditional power grid can not be achieved operational status of equipment for effective monitoring and control, we will not be able to ensure the quality and quality of electricity service. Cloudbased build smart grid information platform enables gathering the parameter of grid operation state, greatly increasing the economic efficiency of power enterprises. Firstly, cloud computing and smart grid briefly described, and then pointed out that cloud computing applications in the smart grid information platform, and specialized of cloud-based smart grid information platform, in order for the power grid enterprises to enhance their level of service and provide effective reference. KEYWORD: cloud computing; smart power grids; information platform; Application 4th International Conference on Mechanical Materials and Manufacturing Engineering (MMME 2016) © 2016. The authors Published by Atlantis Press 202 3 THE MAIN PROBLEM IS STILL THE SMART GRID INFORMATION PLATFORM FACING The transition to a cloud computing data center. Our data center because of the different regions and the degree of information presents different characteristics, some data centers already have a basic cloud computing capabilities, but most data centers still remain in the initial level, to ensure the normal operation of the existing data center power under the premise, gradual transition to cloud computing data center in order to meet future requirements of the development of smart grid. Restricting data transmission problem. State Grid Corporation between provincial branches and there are a lot of data needs to be transmitted, will bring massive data transmission efficiency decreases, taking into account the load balancing device between the cloud node, thus building a wide area network channels to resolve data transmission problem. Security of data transmission. Data Center for Cloud Computing power companies to build internal private cloud, capable of self-maintenance and management, system wide area network data transmission services, according to the third security zone defined security partition, and install proprietary equipment production area and external public network isolation . 4 CLOUD COMPUTING APPLICATIONS IN THE SMART GRID INFORMATION POLICY PLATFORM Integrate and optimize the management of heterogeneous resources. Among the smart grid systems, data resources, information systems between various platforms and mutually dispersed, severe heterogeneity, thus leading to the integration of the quality of information sharing to increase difficulty, unable to effectively improve network management efficiency for the power distribution system electrical work quality management and marketing operations system maintenance upgrade will not be able to effectively meet demand (Jie Yang, 2014). Cloud computing technology enables the power system to effectively integrate the various business data and computing resources on the basis of information for business collaboration platform built on effective, able to satisfy the huge demand for smart grid information resource sharing. Cloud computing network virtualization and application virtualization technology, the server virtualization technology and other resources to achieve each service abstraction, and then realize the difference between the system and the software effectively eliminated by the appropriate method to achieve the effective integration of information resources, and then to optimize the management, greatly improving the efficiency of heterogeneous resources management applications. Distributed storage and management of large volume of data. After application of smart grid information platform construction, customer service requests varied, huge data volume information brought it to the storage and management of data provides a great challenge. Cloud computing technology in general face amount of data each smart grid system and unit collected using forms distributed storage of data to achieve the effective storage, greatly to ensure the security and reliability of data storage. GFS effective use of technology with each node, the master server is responsible for the effective management of the whole file system, the file system and complete the work of the metadata stored in the data block is the main server for data storage block sliced, and by saving three or more redundant backup storage. At the same time, client access and complete access to the main block server information. Fast Power System Parallel Computation and Treatment. Smart grids and information platform for the large volume of data to provide stable operation of the power grid data base, but more critical is the analysis and design of each system operating data, planning and decision-making, and even failures and transient stability, state estimation and intelligent a variety of computing and content analysis and decision-making process, its huge computing needs, general computing system can not reach its goal (Wang, Mengxue, 2015). Cloud computing technology through parallel computing technology has greatly enhanced parallel processing capability of the power system, which provides parallel programming model makes more simple and efficient parallel algorithms. MapReduce as Google made an important parallel programming model, and its role in large data sets in parallel computing plays a very prominent. Parallel processing job results by the client to achieve effective user submitted, via decomposition automated master role, the corresponding task scheduling to working nodes and nodes work completed by the specific calculations and perform the appropriate task. 5 SMART GRID INFORMATION PLATFORM CLOUD COMPUTING ANALYSIS Cloud Computing Smart Grid Information Platform Architecture. Smart grid technology information platform architecture cloud computing include the following several levels and aspects (Yan Cui, 2015): First, that the platform infrastructure layer is the integration of the various hardware resources and related management capabilities of virtualized using virtual technology to achieve the corresponding hardware devices such as computers and network storage devices abstraction, and then complete the automation and optimization of resource data and load management; secondly, the main platform for the integration of the various layers of software

Smart Distribution Grid and Utilization are the important support for the development of Smart City and Smart Grid, meanwhile, the effective data communication and information exchange are the key points to implement them. First, analyze the unified communication method of Smart Distribution Grid and Utilization for each specific business. Then, respectively, from the current reality and future trends, propose two typical implementation:the interface adapter pattern and the integrated pattern, and establish specific implementation patterns, deployment patterns, and pattern evaluations, so as to provide the design of pattern level for the development of Smart Distribution Grid and Utilization.

Shanghai is one of China's highest levels of industrialization and most economically developed regions. In the backdrop of the development of smart grid, smart electric power industry will be to play a very important position in the Shanghai urban area's electric power industry. This paper will focus on the analysis of the present situation of Shanghai urban area's power grid, especially the basic skills and business models of the power demand side. It is researched that the blueprint of the Shanghai urban area's future power grid and achieving methods based on the related smart electricity work carried on in the current Shanghai urban area and its effectiveness, especially, the pilot project. The main work is as follows: the description of the current Shanghai urban area power grid, including the history, development and evolution, load characteristics level, reliability, power distribution automation level and so on. The presented situation of smart power, which mainly includes the information collection system pilot project, electric vehicle charging facilities pilot project, intelligent building pilot project, flexible DC power transmission pilot project, the power FTTH (Fiber to The Home) to households pilot project, especially combine with the smart grid key pilot projects, such as the smart power design and practice of Shanghai World Expo smart grid pilot projects, and point out the current shortage and inadequate of the smart grid. The blueprint and achieving methods of the smart electricity describes the design blueprint of the future smart electricity in Shanghai urban area, and the means and direction to realize, such as to adapt and promote clean energy development, realizing highly smart grid dispatching to meet the electric vehicle and other new electricity consumers of electricity service requirements, efficient use and life cycle management of grid assets, convenient interaction between power users and grid, grid management informationalization and delicacy and playing the role of value-added services potential of the grid infrastructure.

Synthetically analyze the power distribution communication network technology in the smart power grid link. It mainly includes the summary of the smart distribution network, electric power communication backbone network and then layer communication requirements, the network mode and the application mode of WLAN technology in the distribution network, EPON network technology, micropower wireless technology, PTN technology and power broadband wireless systems. State the demand of the smart power distribution business and put forward technical guidance for the smart power distribution communication network scheme. In view of the complex distribution network architecture, more nodes and scattered, complex business types data business needs, put forward the integrated solutions of optical fiber communication as the backbone access, wireless bandwidth, passive optical communication as the coverage, the short distance wireless communication as the main terminal access. It provides a reference for the communication plan of distribution side.

The growth of wind farms in Brazil brings new challenges to the Brazilian electrical system, such as the adequacy of regulation for system operation, the supply-demand balance, the quality of the supplied power, and the system stability. New technologies associated with smart grids will enable an increase in intermittent renewable sources connected to the power distribution system. D-STATCOM (Distribution Static Synchronous Compensator) provides the necessary resources to prevent technical problems in systems with high penetration of wind power plants. It makes possible the wind farms to meet the requirements of network connection as power factor, voltage output and fault ride through requirements, as well as increases the transmission capacity and the network stability. This paper presents the dynamic behavior obtained by computer simulation of a distribution grid at 34.5 kV with D-STATCOM and wind farms. The use of D-STATCOM contributed to increasing the stability margin of the system, allowing the permanence of the three wind farms during fault and post-fault conditions.