The hottest UHV strong dc weak AC supporting power

2022-08-17
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UHV "strong DC and weak AC", supporting power production lag... Can wind power consumption be solved

the guiding opinions on the implementation of the 13th five year plan for renewable energy development (hereinafter referred to as the "guiding opinions") released by the national energy administration a few days ago clearly stipulates that it is necessary to strengthen the implementation of electricity access and market consumption conditions, and give play to the role of trans provincial and trans regional UHV transmission channels in the consumption of renewable energy

in terms of improving the management mechanism of the construction scale of wind power and photovoltaic power generation, the National Energy Administration verifies the annual implementation plan and relevant conditions submitted by the competent energy departments of all provinces (autonomous regions and municipalities), and finally determines the new construction scale of all provinces (autonomous regions and municipalities) in the current year according to the power transmission and consumption conditions promised by the power enterprises in the current year

the scale of wind and solar power generation should be based on the opinions on power consumption capacity issued by electricity

recently, some photovoltaic power generation projects in northern Hebei. 8. The cable connecting the sensor of the low-noise pressure testing machine of the cement fatigue testing machine and the host must not be in order to make it fully realize the importance of concrete vibration. The event that the indirect leader cannot merge before June 30 has attracted attention in the industry. In this regard, the State Power Corporation provided the documents formulated and issued by the national development and Reform Commission and the national energy administration, and pointed out that according to the notice of the national development and Reform Commission and the National Energy Administration on the management of the full guaranteed acquisition of wind power and photovoltaic power generation, the state has made it clear that provinces (regions and cities) that do not meet the minimum guaranteed annual utilization hours of acquisition are not allowed to build new wind power and photovoltaic power station projects

among them, the utilization hours of indemnificatory acquisitions in northern Hebei in 2016 are required to be 1400 hours. However, according to the notice of the National Energy Administration on the monitoring and evaluation of the national renewable energy power development in 2016 (Guo Neng Xin Neng [2017] No. 97 document), the annual utilization hours of photovoltaic power generation in northern Hebei in 2016 was only 1382 hours, which did not meet the specified minimum guaranteed annual utilization hours of photovoltaic power generation acquisition, so it did not meet the merger requirements

the guidance issued this time further clarified that the competent energy departments of all provinces (autonomous regions and municipalities) should take the implementation of renewable energy power transmission and consumption as the basic prerequisite for arranging the scale and layout of renewable energy power construction in the region. Each provincial power company shall study the connection conditions and consumption scheme of the annual new construction scale, and issue opinions on power consumption. The determination and distribution of the annual scale of centralized wind power and photovoltaic power generation should be based on the commitment of provincial power enterprises to invest in the construction of power transmission projects and the opinions on the consumption capacity of the power system

the Guiding Opinions also requires that for large hydropower, wind power and photovoltaic power generation bases, the provincial (District, city) energy authorities and the municipal (county) local government energy authorities should first implement the power consumption market. For the base of local consumption of generated electricity, the relevant provincial energy departments should work with local governments and provincial power enterprises to clarify the power consumption mechanism and safeguard measures; The base for the consumption of generated electricity across provinces and regions should comply with the national energy and power related development plan, and the provincial government and power enterprises at the transmission and receiving end should negotiate and reach a transmission and receiving agreement, transmission and consumption plan

UHV delivers renewable energy according to the plan

requires multi-party cooperation

the guiding opinions points out that the role of inter provincial and inter regional UHV transmission channels to absorb renewable energy should be played. The UHV transmission channels that have been identified by the national energy administration as renewable energy electricity proportion indicators will be assessed according to the identified indicators; For UHV transmission channels without clear indicators, the relevant regulatory agencies will monitor them for a one-year cycle to determine the proportion of renewable energy and channel utilization indicators. The proportion index of renewable energy power transmission should be clearly defined for the new UHV transmission channels in the subsequent planning in areas rich in hydropower, wind energy and solar energy resources, and the channel utilization index should be clearly defined for the UHV transmission channels mainly transporting hydropower

practice has proved that UHV in China is playing an increasingly important role in promoting the large-scale export and consumption of renewable energy. For example, in terms of hydropower transmission, this summer is the fourth year of the full power operation of the three ± 800 kV HVDC transmission projects Xiangjiaba Shanghai, Jinping Southern Jiangsu and Xiluodu western Zhejiang in flood season, which not only helps the large-scale export of Southwest hydropower, but also ensures the power demand of the load center in East China

of course, the full power operation and transmission of renewable energy of some UHV projects are also limited by relevant factors. It is understood that due to the fluctuating and intermittent characteristics of wind power and solar power generation, a certain proportion of thermal power is required to ensure the safe and stable operation of electricity. However, some UHV projects do not operate at full power as planned due to the lag in the production of relevant supporting power supplies

on June 22 this year, Jiuquan Hunan ± 800 kV HVDC transmission project was put into operation, which is China's first large-scale UHVDC transmission project to transmit new energy. The reply on supporting the establishment of a new energy comprehensive demonstration zone in Gansu Province issued by the national energy administration clearly requires that the Jiuquan Hunan UHV DC project ensure that the annual transmission of new energy accounts for more than 40%. "Due to the failure of the supporting power supply at the transmission end and the large-scale hydropower generation in Hunan this year, the transmission level of Jiuhu UHV has not reached the designed maximum transmission capacity, but it still plays a role in the new energy consumption in Hexi region of Gansu and Xinjiang." Introduction of relevant people in China

UHV projects related to power transmission in Inner Mongolia also face similar problems. Mengxi Tianjin South 1000 kV high voltage AC project, Ximeng Taizhou, shanghaimiao Shandong ± 801: the sliding surface of the inlaid steel plate in contact with the lining plate and the dovetail groove surface on the lining plate should be kept clean. The 0 kV High Voltage DC project aims to send Inner Mongolia power to the load centers in North and East China. According to relevant plans, the total transmission capacity of Ximeng UHV AC/DC transmission project is 17.6 million KW, the supporting thermal power is 7.3 million KW, and the wind power is 7 million KW, which can be put into operation successively in. These supporting power sources obviously lag behind the power engineering for years, making it difficult to give full play to the capacity of UHV channel

at the same time, the problem of "strong DC and weak AC" of UHV is prominent, especially the construction of the receiving end in the East and middle is lagging behind, and the ability to undertake large-scale DC is insufficient, which restricts the development of DC transmission capacity. In addition, China's power market mechanism is not perfect, there are inter provincial barriers to cross regional power transactions, as China's economy enters the new normal, the growth of power demand slows down, and some receiving provinces are not active in receiving external electricity from the region, which also affect the transmission capacity of power channels

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