To build a new type of power system with new energy as the main body, we need to balance safety and development and adhere to the bottom line of safe power supply. In the new stage of development, the new energy industry should aim at the positioning of the main power supply, use new technologies, promote new models, solve new problems, and actively improve its own power support capability, so as to promote the steady and long-term development of the industry and achieve high-quality development.
I. Integrate and apply new technologies to accelerate the transformation of new energy sources into reliable, flexible and friendly main power sources
One of the reasons for the influence of large-scale and high proportion of new energy on power system operation and power supply security lies in the intermittence, fluctuation and randomness of new energy generation output. At present, the installed capacity of new energy power generation in China is close to 25%, and the generating capacity is close to 10%. New energy does not have the system friendly characteristics similar to conventional power supply. It is estimated that around 2030 ~ 2035, new energy generation is expected to account for more than 50% of installed power generation, and will become the main power source of the new power system. Relying only on conventional power supply projects of the remaining scale can not achieve safe and reliable power supply. Therefore, it is urgent to integrate and apply new technologies in related fields, accelerate the improvement of the system friendly characteristics of new energy power generation projects, and enhance the power support capability.
According to the current progress of relevant technologies, during the "14th Five-year Plan", technical measures such as integrated application of new energy efficient power generation, long-range and high-precision new energy power prediction, joint scheduling and operation of wind storage and wisdom, large-scale low-cost and long-life energy storage can be adopted. We will speed up the construction of a number of systemically friendly green power stations with reliable power generation, flexible regulation, friendly grid connection and other functions and performance indicators. In terms of reliable power generation, can be combined with the long dimension precision of new energy power prediction technology and the actual demand of power system, reasonable charge and discharge of storage plan ahead of time, the key to ensure the system have a certain peak peak power shortage period support ability, will the confidence the output level of new energy power generation by about 5% to 20% ~ 30% of the higher level, Reduce the installed demand of traditional power supply and alleviate the power supply guarantee problem during peak power shortage period.
In terms of flexible regulation, energy storage and intelligent joint scheduling technology can be used comprehensively. On the basis of ensuring the efficient absorption and utilization of new energy power of the power station, the remaining regulation capacity of energy storage can further provide regulation services for the system and surrounding new energy projects, and become a friendly regulation power source. In the friendly connections, can improve the system by optimizing the friendly green power station project, the inertia of primary frequency support, fault crossing, fast regulating interconnection technical performance indexes such as, reducing the failure probability of new energy projects and the overall system, enhance the level of safe operation accidents and in extreme cases, to ensure safe and reliable power supply.
Second, promote the use of new models, improve the overall allocation of new energy power generation and local supply security capacity
The basic characteristics of China's energy resource endowment and misplacement distribution of electricity load determine that it is still necessary to develop new energy resources in the northern and western regions on a large scale in the future, and rely on large power grids to transport them to the load centers in the central and eastern regions, as one of the important ways to ensure the power supply in the central and eastern load centers. Therefore, it is of great significance to improve the power transmission capacity of inter-provincial and inter-regional transmission channels and the proportion of new energy in electric power supply in the central and eastern regions. According to the National Energy Administration about 2020 annual national renewable energy power development of monitoring and evaluation results, the operation of the state grid article 18 uhv channel power transmission of renewable energy accounted for 37%, the part has been put into operation of uhv transmission channel utilization rate is low, transmission capacity and new energy power accounted for further room for improvement.
In order to improve the scale and level of cross-provincial allocation of new energy power, the 14th Five-Year Plan can be carried out from two aspects: stock and increment. For the stock trans-provincial and trans-regional outbound transmission channel, it can give full play to the regulation ability of the transmitting and receiving end system, and use the short-term and ultra-short-term power prediction technology of new energy to optimize the power transmission curve rolling, so as to improve the power transmission capacity of the channel and the proportion of new energy electricity. Inter-district delivery channels for new provinces can promote use of "landscape water storage" pluripotent complementary pattern, construction of high efficiency, high energy accounted for China to send transmission channel, in some areas, with appropriate conditions can explore the high proportion of new energy and even "scenery" storage "scenery water storage" integration of pure renewable energy delivery mode.
On the other hand, it is of great significance to promote the local development and utilization mode of new energy with "integration of source network, charge and storage" for improving the local supply and guarantee capacity of new energy power generation. In the western and northern regions, combined with the industrial structure transfer and new energy resources conditions, new energy can be promoted to provide local green power for the power load of high-load industries, and try to increase the proportion of green power consumption of new energy. In important cities, industrial parks and remote areas in the central and eastern regions, as well as in the northern and western regions, it is possible to promote the construction of distributed micro-grid with new energy as the main body and self-use as the main body, and give full play to the flexible layout advantage of distributed system close to end users. Make it become an important measure to guarantee the power supply of important loads in central cities, meet the demand of green power consumption in industrial parks, and solve the power supply problems in remote areas. It is compatible and complementary with the large power grid, and greatly improves the local power supply guarantee ability.
Third, study and solve new problems, and give play to the power support and guarantee role of distributed photovoltaic and offshore wind power
The central and eastern regions and southern regions are the power load centers in China. In recent years, with the increasing constraints of ecological environmental protection and land resources, it is increasingly difficult to develop coal power and large-scale centralized new energy, and the pressure of power supply is also increasing. Last winter, extreme cold weather occurred in Hunan, Jiangxi and other regions, and the power load increased rapidly in a short period of time. Under the circumstance that all kinds of power sources and large power grids, such as new energy, could not provide effective support, there appeared a large range of power supply guarantee problem, which is worth pondering. Under such circumstances, the development of distributed photovoltaic and offshore wind power has become an important measure for the development and utilization of new energy and the improvement of power supply security in the central and eastern and southern regions. At present, the grid-connected consumption problems of distributed photovoltaic and offshore wind power have not yet appeared in a large scale. However, in the long run, with the sustained and rapid development of distributed photovoltaic and the gradual expansion of offshore wind power to the deep sea, overall planning and advanced research are needed to solve the new problems that may occur in the development process.
On the one hand, distributed photovoltaic has strong commercial competitiveness in the era of parity, flexible layout and huge market potential. At present, the installed installed capacity of distributed pv in Shandong and Zhejiang has exceeded 10 million kW, and that in Hebei and Jiangsu has approached 10 million kW. Considering the centralized PV, the grid-connected installed capacity of pv in Hebei and Shandong has exceeded 20 million kW. During the 14th Five-Year Plan period, under the guidance of national policies, it is expected that the development of distributed pv in the central and eastern regions will be further accelerated. From the perspective of the system is running on a large scale high percentage after the photovoltaic (pv) grid, will change the net load characteristics of electric power system, presents the typical curve "duck", requires power system have more fast and flexible adjustment ability, can cause restriction to the further development of photovoltaic power generation, will also bring pressure to the power grid power supply security ability. At present, in some parts of central and eastern China, it has been difficult to absorb photovoltaic power generation at noon. Therefore, it is necessary to improve the flexible regulation capacity of the power system, promote the construction of the power market, guide all kinds of energy storage, adjustable load and other resources through flexible market price signals, and provide support for the local development and utilization of photovoltaic.
On the other hand, the total grid-connected installed capacity of China's offshore wind power projects has exceeded 10 million kw. During the 14th Five-year Plan period, some key coastal provinces and autonomous regions are planning to build large scale offshore wind power projects, and the development of offshore wind power shows a momentum of acceleration, and the difficulty of collecting, sending, and connecting the grid will continue to increase, requiring special studies. At the same time, the planning and construction work of the far-reaching sea breeze power is gradually put on the agenda. Because of the longer distance of offshore power transmission, the larger scale of intensive development and the higher voltage level of access to the power grid, the development of the far-reaching sea breeze power project will be more closely connected with the large power grid. Therefore, it is necessary to coordinate the planning of far-reaching offshore wind power in coastal areas with the development planning of power system and power grid, study and solve the problems of grid connection, transmission, consumption and utilization of far-reaching offshore wind power in advance, and give full play to the power support and guarantee role for the central and eastern coastal areas.
Wuhan Xinshengneng is a professional power testing equipment manufacturer. We pay close attention to the development and trends of power grid related industries. For more information, visit wuhan Xinshengneng's official website: www.whxsn.com
