Intelligent grid is called "Grid 2.0", which is based on an integrated, high-speed two-way communication network, through advanced sensing and measurement technology, advanced equipment technology, advanced control methods and advanced decision support system technology Application to achieve the goals of reliability, security, economy, efficiency, environmental friendliness and safe use of the power grid. Its main features include self-healing, incentives and protection of users, resistance to attacks, providing power quality that meets user needs, and allowing various forms of power generation The connection of electricity, the start-up of the electricity market, and the optimized and efficient operation of assets.
1. Introduction to intelligent grid
U.S. Department of Energy "Grid 2030": A fully automated power transmission network capable of monitoring and controlling each user and grid node, ensuring the two-way flow of information and power between all nodes in the entire transmission and distribution process from power plants to end users .
China Internet of Things School-Enterprise Alliance: Intelligent grid consists of many parts, which can be divided into: smart substation, smart distribution network, smart energy meter, smart interactive terminal, smart dispatch, smart home appliances, smart power buildings, smart city power grid , Intelligent power generation system, new energy storage system.
European Technology Forum: An electricity transmission network that integrates all activities of all users connected to the grid to efficiently provide continuous, economical and secure electricity.
State Grid China Electric Power Research Institute: Based on the physical grid (China's smart grid is based on a strong grid with UHV grid as the backbone grid and coordinated development of grids of various voltage levels), modern advanced sensing and measurement technology, A new type of power grid formed by the high integration of communication technology, information technology, computer technology and control technology with the physical power grid. It aims to fully meet users' demand for electricity and optimize resource allocation, ensure the safety, reliability and economy of power supply, meet environmental protection constraints, ensure power quality, and adapt to the development of power market, etc., to achieve reliable and economical power for users. , clean, interactive power supply and value-added services.
1.1 Background of intelligent grid
The development of intelligent grid is still in its infancy in the world, and there is no common precise definition. Its technology can be roughly divided into four areas: advanced measurement system, advanced power distribution operation, advanced transmission operation and advanced asset management. The main function of the advanced measurement system is to authorize the user to establish a connection between the system and the load, so that the user can support the operation of the power grid; the core of the advanced power distribution operation is online real-time decision-making command, the goal is disaster prevention and control, and the prevention of large-scale cascading failures The main function of advanced transmission operation is to emphasize congestion management and reduce the risk of large-scale outage; advanced asset management is to install a large number of advanced sensors in the system that can provide system parameters and equipment (asset) "health" status, and collect the Real-time information is integrated with processes such as resource management, simulation and simulation to improve the operation and efficiency of the power grid. The intelligent grid is an important application of the Internet of Things. The article "Study on the Architecture of Smart Grid Information System" published in "Acta Computer Science" discusses it in detail, and analyzes the architecture of the intelligent grid information system.
1.2 Market share of intelligent grid
The establishment of intelligent grid is a huge historic project. Many complex intelligent grid projects are currently underway, but the gap is still huge. For providers of intelligent grid technologies, the driving challenges are distribution network system upgrades, distribution station automation and power transportation, intelligent grid networks, and smart meters. According to the latest report of Parker Research Institute, the intelligent grid technology market will grow from 33 billion US dollars in 2012 to 73 billion US dollars in 2020, and the cumulative market will reach 494 billion US dollars in 8 years.
During the "Twelfth Five-Year Plan" period, my country will build an UHV AC line of "three vertical, three horizontal and one ring networks", and build 11 UHV DC transmission projects, with an investment of up to 300 billion yuan; the investment during the "Thirteenth Five-Year Plan" period is slightly There has been a slowdown, and the investment quota has reached 250 billion yuan.
By 2015, the State Grid's large-scale and long-distance power transmission capacity will reach 250 million kilowatts, and the annual transmission of electricity will be 1.15 trillion kilowatt-hours, which can support the consumption and transmission of 145 million kilowatts of clean energy power generation, which can meet the needs of more than 1 million people. According to the requirements for the use of electric vehicles, the resource optimization allocation capability, economic operation efficiency, safety level and intelligence level of the power grid will be comprehensively improved.
2. Overseas application of power intelligent grid
In terms of the foundation of power grid development, the power demand in various countries tends to be saturated. After years of rapid development, the power grid structure tends to be stable and mature, and it has relatively sufficient power transmission and distribution supply capacity.
Germany formulated the "E-Energy" plan, with a total investment of 140 million euros. During the four years from 2009 to 2012, intelligent grid demonstration experiments were carried out in six locations across the country. At the same time, it also conducts demonstration experiments on wind power generation and electric vehicles, and tests Internet management power consumption. Large companies such as Germany's Siemens, SAP and Switzerland's ABB have all participated in this plan. It is estimated that the annual market size of Siemens' intelligent grid in 2014 will reach 30 billion euros, and plans to seize 20% of the market share and secure orders of 6 billion euros per year. Level and intelligent level will be fully improved.
3. Features of intelligent power grid
Compared with the existing power grid, the intelligent grid reflects the remarkable characteristics of high integration of power flow, information flow and business flow. Its advancement and advantages are mainly manifested in:
3.1 It has a strong grid infrastructure and technical support system, which can resist various external interference and attacks, and can adapt to the access of large-scale clean energy and renewable energy. The robustness of the grid has been consolidated and improved.
3.2 The organic integration of information technology, sensor technology, automatic control technology and grid infrastructure can obtain the panoramic information of the grid, and detect and predict possible failures in time. When a fault occurs, the power grid can quickly isolate the fault and realize self-recovery, thereby avoiding the occurrence of large-scale power outages.
3.3 The wide application of technologies such as flexible AC/DC transmission, grid-plant coordination, intelligent dispatching, power energy storage, and distribution automation makes the grid operation control more flexible and economical, and can adapt to a large number of distributed power sources, micro-grids, and electric vehicle charging. Access to discharge facilities.
3.4 The comprehensive application of communication, information and modern management technology will greatly improve the efficiency of power equipment, reduce power loss, and make the operation of the power grid more economical and efficient.
3.5 Realize the high integration, sharing and utilization of real-time and non-real-time information, display a comprehensive, complete and detailed power grid operation status map for operation management, and at the same time provide corresponding auxiliary decision support, control implementation plans and response plans.
3.6 Establish a two-way interactive service model, users can learn about power supply capacity, power quality, electricity price status and power outage information in real time, and arrange electrical appliances reasonably; power companies can obtain users' detailed electricity consumption information and provide them with more value-added services.
4. The development prospect of intelligent grid
4.1 The trend of intelligent grid
During the "Twelfth Five-Year Plan" period, the State Grid will invest 500 billion yuan to build the "three horizontal and three vertical" UHV backbone grids and 13 long-distance tributary power transmission projects that connect large energy bases and main load centers, and initially build the core A world-class robust intelligent grid.
The "Strong Smart Grid Technical Standard System Plan" formulated by State Grid clearly defines the roadmap for strong intelligent grid technical standards, and is the world's first programmatic standard used to guide the development of smart grid technology. The plan of the State Grid Corporation of China is to basically build a strong smart grid featuring informatization, automation, and interaction by 2015, and form three synchronous grids with North China, Central China, and East China as the receiving end, and Northwest and Northeast Power Grids as the sending end. The resource allocation capability, economic operation efficiency, safety level, technological level and intelligent level of the power grid have been comprehensively improved.
4.1.1 Smart grid is an inevitable trend of grid technology development. Communication, computer, automation and other technologies have been widely and deeply applied in the power grid, and organically integrated with traditional power technology, which has greatly improved the intelligence level of the power grid. The application of sensor technology and information technology in the power grid provides technical support for system state analysis and auxiliary decision-making, making it possible for the power grid to heal itself. The mature development of dispatching technology, automation technology and flexible power transmission technology provides a basic guarantee for the development and utilization of renewable energy and distributed power. The improvement of the communication network and the popularization and application of user information collection technology have promoted the two-way interaction between the power grid and users. With the further development and application of various new technologies and their high integration with the physical grid, the intelligent grid emerges as the times require.
4.1.2 The development of smart grid is an inevitable choice for social and economic development. In order to realize the development, transmission and consumption of clean energy, the grid must improve its flexibility and compatibility. In order to resist increasingly frequent natural disasters and external disturbances, the power grid must rely on intelligent means to continuously improve its security defense capabilities and self-healing capabilities. In order to reduce operating costs and promote energy conservation and emission reduction, the operation of the power grid must be more economical and efficient. At the same time, intelligent control of electrical equipment must be carried out to reduce power consumption as much as possible. The rapid development of distributed power generation, energy storage technology, and electric vehicles has changed the traditional power supply and consumption model, and promoted the continuous integration of power flow, information flow, and business flow to meet increasingly diverse user needs.
4.2 Plan for intelligent grid
Japan plans to popularize intelligent grids in 2030, and at the same time, the government and the people will make every effort to promote the construction of intelligent grids overseas. In the storage battery field, Japanese companies aim to achieve 50% of the global market share and obtain a market of about 10 trillion yen. Japan's Ministry of Economy, Trade and Industry has established the "Research Association on International Standardization of Next Generation Energy Systems", and Japan and the United States have established joint experiments on smart grids in Okinawa and Hawaii.
It was learned from the China Electricity Council that in 2020, China will build UHV synchronous power grids in North China, East China, and Central China as the center, Northeast UHV power grids, and Northwest 750 kV power grids as sending ends, connecting major coal power bases, large hydropower bases, and large power grids. Nuclear power bases, large renewable energy bases, strong smart grids with coordinated development of power grids at all levels. The UHV synchronous power grids in North China, East China, and Central China have formed a "five vertical and six horizontal" main grid.
4.3 The direction of intelligent grid
Driven by the awareness of green energy saving, the intelligent grid has become a key area of development of countries all over the world.
A smart grid is a power network that is self-healing, actively engages consumers, recovers from attacks and natural disasters in a timely manner, accommodates all generation and energy storage, accommodates new products, services and markets, optimizes asset utilization and operating efficiency, and provides The digital economy delivers power quality.
The smart grid is based on an integrated, high-speed two-way communication network. Environmentally friendly and safe to use with efficient operation.
Its development is a gradual and gradual evolution, a complete revolution, and a product of the coordinated development of existing technologies and new technologies. It also covers a wider range in addition to networks and smart meters.
Build a strong smart grid with the UHV grid as the backbone grid, coordinate the development of grids at all levels, and feature informatization, automation, and interaction, and comprehensively improve the security, economy, adaptability, and interaction of the grid. Strength is the foundation , intelligence is the key.
4.4 Significance of intelligent grid
Its significance is reflected in the following aspects:
4.4.1 Possess a strong ability to optimize resource allocation. After the completion of my country's intelligent grid, it will realize the cross-regional, long-distance, large-capacity, low-loss, and high-efficiency transmission of large-scale hydropower, large-scale coal power, large-scale nuclear power, and large-scale renewable energy, and the inter-regional power exchange capacity will be significantly improved.
4.4.2 Have a higher level of safe and stable operation. The security and stability of the power grid and the reliability of power supply will be greatly improved. The defense lines at all levels of the power grid will be closely coordinated, with the ability to resist sudden events and serious failures, effectively avoid the occurrence of large-scale cascading failures, and significantly improve the reliability of power supply. Reduce power outage losses.
4.4.3 Adapt to and promote the development of clean energy. The power grid will have control mechanisms such as wind turbine power prediction and dynamic modeling, low-voltage ride-through and active and reactive power control, and rapid adjustment of conventional units. Combined with the popularization and application of large-capacity energy storage technology, the operation control capability of clean energy grid connection will be significantly improved. Improve and make clean energy a more economical, efficient and reliable way of supplying energy.
4.4.4 Realize highly intelligent grid dispatching. Fully build a horizontally integrated and vertically connected intelligent grid dispatching technical support system to realize online intelligent analysis, early warning and decision-making of the grid, as well as efficient regulation of various new power generation and transmission technology equipment and lean control of the AC-DC hybrid grid.
4.4.5 To meet the service requirements of new power users such as electric vehicles. A complete electric vehicle charging and discharging supporting infrastructure network will be formed to meet the development needs of the electric vehicle industry, adapt to user needs, and realize efficient interaction between electric vehicles and the power grid.
4.4.6 Realize efficient utilization of power grid assets and full life cycle management. It can realize the overall management in the whole life cycle of power grid facilities. Through intelligent grid dispatching and demand-side management, the utilization hours of grid assets have been greatly increased, and the utilization efficiency of grid assets has been significantly improved.
4.4.7 Realize convenient interaction between power users and the grid. An interactive platform for intelligent power consumption will be formed to improve demand-side management and provide users with high-quality power services. At the same time, the grid can make comprehensive use of distributed power sources, smart energy meters, time-of-use electricity price policies, and electric vehicle charging and discharging mechanisms to effectively balance grid loads, reduce load peak-valley differences, and reduce grid and power supply construction costs.
4.4.8 Realize informatization and lean management of power grid. A communication network system covering all aspects of the power grid will be formed to realize functions such as power grid data management, comprehensive supervision of information operation and maintenance, power grid space information services, and integration of production and scheduling applications, and fully realize the informatization and leanness of power grid management.
4.4.9 Give full play to the value-added service potential of grid infrastructure. While providing electricity, it also serves the national strategy of "integration of three networks", provides users with integrated services such as community advertising, Internet TV, and voice, and provides platform support for informatization and interaction in industries such as water supply, heat, and gas, and expands and improves The scope and capability of grid infrastructure value-added services will strongly promote the development of smart cities.
4.4.10 Promote the rapid development of grid-related industries. The electric power industry is a capital-intensive and technology-intensive industry with the characteristics of large investment and long industrial chain. The construction of intelligent grid is conducive to promoting the technological upgrading of equipment manufacturing and communication information industries, and laying the foundation for my country to occupy the commanding heights of the world's electric power equipment manufacturing field.
The intelligentization of the power grid plays an important role in promoting the development of the world economy and society. The construction of intelligent grid plays an important role in coping with global climate change and promoting the sustainable development of the world economy and society. Mainly manifested in:
Promote the development and utilization of clean energy, reduce greenhouse gas emissions, and promote the development of a low-carbon economy. Optimize the energy structure, realize the complementarity of various energy forms, and ensure the security and stability of energy supply. Effectively improve the efficiency of energy transmission and use, and enhance the safety, reliability and flexibility of power grid operation. Promote technological innovation in related fields, promote technological upgrading of equipment manufacturing and information communication industries, expand employment, and promote sustainable social and economic development. Realize the two-way interaction between the power grid and users, innovate the traditional model of power services, provide users with more high-quality and convenient services, and improve people's quality of life.
The interactive grid is not only the basic model of the next generation global grid, but also the core of China's grid modernization
In fact, the essence of interactive grid is energy substitution, compatible utilization and interactive economy. Technically speaking, the interactive grid should be the integration of the most advanced communication, IT, energy, new materials, sensors and other industries. Synthesis has a direct comprehensive effect on promoting the new technological revolution. Therefore, the intelligent grid has the characteristics of reliability, self-healing, economy, compatibility, integration and security. I think: The essence of the interactive grid theory is to use the innovative standards and technical means of the information revolution to promote the innovation and upgrading of the most important property of the industrial revolution-the grid system on a large scale, and to establish the interaction between consumers and grid managers.