The world's first county-level 100% new energy new power system can realize 100% new energy independent power supply in Guangshui City, Suizhou City, Hubei Province, with a population of more than 200,000. This new type of power system is a future-oriented new form of power grid with new energy power supply as the main body, flexible interconnection with the large power grid, and coordinated interaction between source, network, load and storage.
As of August 28, a new power system powered by 100% wind and light new energy has been in stable trial operation for 241 days in Guangshui City, Suizhou City, Hubei Province. It is not only a practical and realistic power grid that can ensure that wind and light new energy generation can be generated and used, but also an open test platform with the characteristics of future power grids.
As one of the top ten science and technology demonstration projects of the State Grid Corporation of China, the world's first county-level 100% new energy new power system has been implemented in Guangshui City, which can realize Guangshui's 100% new energy independent power supply, and the population of the supply area exceeds 200,000. This new type of power system is a future-oriented new form of power grid with new energy power supply as the main body, flexible interconnection with the large power grid, and coordinated interaction between source, network, load and storage.
What is the significance of building this new power system? How can it serve social and economic development?
Why the new power system is implemented in Guangshui
At the beginning of June this year, the National Energy Administration organized 11 research institutions to publish the "Blue Book on the Development of New Power System". The blue book pointed out that the new power system has four important characteristics: safe and efficient, clean and low-carbon, flexible and flexible, and intelligent integration.
Statistics show that carbon dioxide emissions from energy activities in my country account for about 88% of total carbon dioxide emissions, and carbon emissions from the power industry account for about 42% of carbon emissions from the energy industry. To achieve the "double carbon" goal, energy is the main battlefield, electricity is the main force, and the new power system is the key carrier.
According to the definition given by the National Grid Operation and Control Standardization Technical Committee, the new power system is based on a strong smart grid as a hub platform, supported by source-grid-load-storage interaction and multi-energy complementarity, and is clean, low-carbon, safe and controllable, flexible and efficient , intelligent, friendly, open and interactive power system with basic characteristics.
Why should the traditional power system turn to the new power system?
With the development of new energy sources, my country's traditional power system is facing three major difficulties: on the power consumption side, the power load continues to soar; On the power grid side, a large amount of new energy power is connected, which poses a certain threat to the security of the power system.
The relevant person in charge of the National Energy Administration believes that the construction of a new power system is a complex and arduous system engineering, which requires overall planning of path layout, scientific deployment, and orderly advancement.
With its rich scenery resources, Guangshui has unique conditions for pilot demonstrations.
Suizhou is the region with the highest proportion of new energy installed capacity and the largest cumulative power generation in Hubei. As of the end of July, Suizhou's new energy grid-connected installed capacity reached 3.1919 million kilowatts, and the new energy penetration rate reached 267.93%, that is, the new energy installed capacity reached about 2.68 times the maximum load. At present, Guangshui new energy installed capacity is 244 megawatts, the maximum load is 61 megawatts, and the new energy penetration rate has reached 400%.
At the same time, the Guangshui Power Grid belongs to the terminal power grid, which can be easily separated from the main grid. It has the ability to build an adjustable proportion of new energy installed capacity (in extreme cases, the proportion of new energy installed capacity is 100%), a variable proportion of flexible loads, and an electromechanical-electromagnetic environment. The combined multi-form network construction conditions can provide a test site for technologies such as source-network-load-storage interaction.
In December 2021, State Grid Hubei Electric Power explored the construction of the world's first county-level 100% new energy new power system technology demonstration project in Guangshui City, with a power supply area of 418 square kilometers, covering major commercial, industrial and residential customers in Guangshui City. Explore new ways for the grid to better access and absorb new energy, and help transform the energy structure.
Flexible interconnection with the large power grid
"The new power system of Guangshui New Energy is still in the third stage of commissioning, and the overall operation is stable. It has initially verified the stability of the 110 kV system independently supported by wind, light and storage." State Grid Hubei Electric Power Co., Ltd. Power Science Research According to Hu Pan, a senior engineer at the Institute's New Power System Research Center, Guangshui's 100% new energy new power system is a new power system form "supported by the large power grid, with new energy supply as the main body, and real-time coordinated and balanced operation of the source network, load and storage".
As an independent grid system, Guangshui 100% new energy new power system can operate independently. But its relationship with the large power grid is not non-interference, but flexible and flexible interaction. Wind and photovoltaic power generation "look at the sky to eat", and the new energy and new power system has great uncertainty, and the large power grid can guarantee it.
Hu Pan said that the power system is connected to the large power grid and cannot do without a key device—the energy router. The energy router is equivalent to a valve, which is similar to a WiFi network router. When the energy router is turned on, the new energy new power system "holds hands" with the large power grid; when it is turned off, it "breaks up" with the large power grid.
Unlike the traditional power system, which enters the load side from the power source side through power transmission, power transformation, and distribution, the voltage level is from high to low, and the power flow is unidirectional. With the help of energy routers, the new energy new power system can not only take power from the large power grid, but also act as a local When there is surplus wind power and photovoltaic power, it can also reversely transmit power to the large power grid to realize flexible interconnection with the large power grid.
Guangshui 100% new energy new power system is a 100% new energy new power system with the largest power supply scale within 100 megawatts and the largest proportion of flexible loads, all powered by wind power and photovoltaics and capable of long-term independent operation. A nearly zero-inertia, full-electricity 100-megawatt high-proportion new energy power system can realize 100% new energy power supply time accounting for more than 70% of the year, and new energy power supply accounting for more than 80% of the year. At the same time, 4 new energy electric fields, 1 energy router station, 5 optical storage charging stations, 2 substations, 17 feeder lines, 703 substations and related user facilities and energy storage facilities of the Guangshui Demonstration Project have been modeled. Digital twin grid. The system can also be used to study key issues such as voltage stability, frequency stability, power balance, and fault characteristics under new power systems, and provide real test scenarios for innovations and breakthroughs in the theoretical construction of new power systems.
Technological innovation supports stable operation
The construction of a new power system needs to change the traditional power source structure, load characteristics and grid form, and the design and construction of the future power grid must adapt to the complexity of the new power system.
To this end, the scientific research team of Guangshui Demonstration Project has developed the world's first source-grid-load-storage collaborative control system that can support the efficient and stable operation of a 100-megawatt new energy grid. It can coordinate real-time control of distributed power sources, energy storage, and energy routers. Power electronics equipment can realize voltage and frequency stability under various extremely complex power fluctuation scenarios, especially when 100% new energy is independently connected to the network, and can meet various needs such as green and efficient when the system is connected to the network, and safe and reliable when the isolated network is running. At the same time, the scientific research team also developed a new energy and energy storage unit set network controller, and verified the characteristics of the whole station network in the real power grid for the first time, so that the new energy power generation equipment and energy storage power supply have the same characteristics as coal power, hydropower, etc. Similar performance to conventional power supplies.
Since the country proposed to build a new power system, my country's power grid enterprises have taken ensuring energy and power security as the basic premise, meeting the power demand of economic and social development as the primary goal, taking the maximum consumption of new energy as the main task, and taking a strong smart grid as the hub platform , and strive to build and improve my country's new power system.
To further improve my country's new power system, we can combine the conclusions drawn from the small-scale real scene research with the actual development path of the increasing proportion of new energy, build a digital twin power grid, and realize the system's panoramic perception and intelligent decision-making. Intelligent algorithms are used to support and ensure the stable operation of the new power system.
Wu Yingzi, Secretary of the Party Committee and Chairman of the State Grid Hubei Electric Power Co., Ltd., said: "In the next step, the company will fully implement the work plan to take the lead in building a new power system in Hubei, and strive to build the first cross-regional new power system in Hubei in 2024. system, providing a complete set of solutions in Hubei for the large-scale construction of new power systems."