"Faced with the clarification of the completion date of the 'double carbon' target, the task facing China's power industry is very arduous. During the "14th Five-Year Plan" period, the State Grid plans to construct UHV projects "24 to 14 straight", involving more than 30,000 kilometers of lines. The transformation capacity is 340 million kVA, and the total investment is 380 billion yuan. In 2022, the State Grid plans to start construction of 13 UHV lines of "10 AC and 3 DC".

The reporter recently learned that the approval of UHV projects will be accelerated in 2022, and all planned projects are expected to be approved. The scale of UHV construction in the next four years will be unprecedented. A person familiar with the matter revealed to reporters that "in 2022, the State Grid plans to start construction of 13 UHV lines of '10 interchanges and 3 directs'".

According to the interviewed industry insiders, in the context of carbon peaking and carbon neutrality, strengthening grid construction, especially UHV construction, can effectively solve the problem of my country's high proportion of renewable energy grid-connected and large-scale deployment across provinces and regions. the problem. As an important measure to build a new power system, AC and DC UHV transmission projects will become the key investment direction of the "14th Five-Year Plan" power grid.

It is necessary to strengthen the construction of inter-provincial and inter-regional channels

The outline of the "14th Five-Year Plan" proposes to build clean energy bases and five offshore wind power bases on nine continents including the Yalong River Basin, Songliao, North Hebei, Jizibend of the Yellow River, and the upper reaches of the Jinsha River. Represented by the clean energy bases on the nine continents, during the "14th Five-Year Plan" period, key new energy development areas include Xinjiang, Yungui, southeastern Tibet, Qinghai, Gansu, western Mongolia, and northeast China, which are 1,000-3,000 meters away from the eastern load center. kilometer.

To achieve long-distance energy delivery, UHV DC, as an electric "express", plays an important role. Huang Xuenong, director of the Electric Power Department of the National Energy Administration, once made it clear that in the western region, northern region, and areas rich in new energy resources, it is necessary to scientifically plan and deploy a number of new energy-based power bases and power transmission channels to achieve new energy power. Global optimization configuration.

The experts interviewed in the industry agreed that with the continuous advancement of the new energy base, the existing UHV DC lines have been gradually bundled, and it is expected that the UHV DC lines will be built around the large base during the "14th Five-Year Plan" period.

"The northwest and southwest regions have outstanding clean energy resource endowments and will serve as the main transmission end of UHV in my country for a long time." Zhang Ning, a senior researcher at the State Grid Energy Research Institute, said in an interview with reporters that building a new power system needs to solve the consumption of clean energy. UHV can not only support the optimal allocation of resources in a wide range, but also play the role of cross-regional regulation and mutual assistance. With the gradual increase in the penetration rate of new energy, a more flexible and optimized operation mode is adopted to tap the output and load of new energy in different regions. The timing complementarity of demand enables cross-regional peak regulation and backup.

After the large-scale launch of UHV and inter-provincial and inter-regional power transmission projects, the problem of new energy consumption is expected to be alleviated. Taking the Central China Power Grid as an example, the ±800kV Yazhong-Jiangxi UHV DC, Shaanwu UHV DC and 1000kV Nanchang-Changsha High Voltage AC projects were put into operation last year, especially the ±800kV Yazhong-Jiangxi UHV After the DC project is put into operation, it has the capacity to transmit 4.6 million kilowatts, which effectively relieves the shortage of power supply in the central China and Jiangxi power grids during the summer, and relieves the pressure of water abandonment in the Sichuan power grid during the flood season. After the 1000 kV Changsha-Nanchang UHV AC project was put into operation, the pattern of the terminal power grid in Hunan and Jiangxi was changed, and the three provinces of Hubei, Hunan and Jiangxi formed a new "triangle" connection pattern.

The research of CITIC Construction Investment believes that with the improvement of domestic grids, the electrical distance between substations is gradually shortened. The most effective linking method is to use flexible DC technology to interconnect regional power grids back-to-back, improve the power exchange and accident support capabilities of the power grid, and alleviate traffic. DC influences each other and reduces the influence of AC faults.

Start a new round of UHV line construction

A person familiar with the matter told reporters, "The country will start a new round of UHV construction on a large scale in 2022, and the scale of construction is unprecedented."

The reporter combed and found that since my country began to explore the UHV demonstration project in 2006, it has experienced three rounds of great development so far. The first round was from 2011 to 2013, planning to build "three horizontal and three vertical" UHV backbone grids and 13 DC transmission projects, forming a large-scale "West-East Power Transmission" and "North-South Power Transmission" pattern; the second round From 2014 to 2016, the National Energy Administration proposed to accelerate the construction of 12 key transmission channels in the Air Pollution Prevention and Control Action Plan, and to promote the construction of 9 UHV lines; the third round is from 2018 to 2020, as a "new infrastructure" investment trust. At the bottom of the economy, UHV ushered in rapid development.

The reporter was informed that during the "14th Five-Year Plan" period, the State Grid plans to construct a UHV project of "24 interchanges and 14 straight lines", involving more than 30,000 kilometers of lines, a substation conversion capacity of 340 million kVA, and a total investment of 380 billion yuan. In 2022, the State Grid plans to start construction of "10 exchanges and 3 direct lines".

The reporter learned from the Sichuan Electric Power Company that it is planning a 1,000 kV Sichuan-Chongqing UHV AC project, which is an important transmission channel in the national "14th Five-Year Plan" plan. The power supply guarantee capability ensures the safe and stable operation of the Sichuan-Chongqing power grid.

"According to the plan, the Ganzi-Tianfu South-Chengdu East, Tianfu South-Chongqing UHV AC project will be constructed, including 3 new Ganzi, Tianfu South, and Chengdu East UHV substations in Sichuan, Tongliang UHV substation in Chongqing, and new substations. The capacity is 24 million kVA." The relevant person in charge of State Grid Sichuan Electric Power revealed to reporters, "Strive to complete the approval in the first half of 2022 and start construction."

Effectively stimulate upstream and downstream industries

In Zhang Ning's view, UHV can not only effectively support the large-scale optimal allocation of clean energy and help achieve carbon peaking and carbon neutrality goals, but also improve the power supply guarantee capability in the eastern and central regions. In addition, the UHV investment scale is large and the industrial chain is long. The construction of UHV projects can effectively stimulate the development of upstream and downstream related industries and promote economic growth.

It is understood that in addition to high-voltage electrical switchgear, new materials, converter valves, cables, transformer equipment, machinery and other related industries, the UHV industry chain can also rely on 5G to promote the development of high-tech such as the Internet of Things and chips.

Zhu Yue, an analyst at CITIC Construction Investment, predicted that during the "14th Five-Year Plan" period, the UHVDC project will be accelerated, and the DC business revenue of related companies such as converter valves and thyristors for high-voltage DC valves will break through the high point in 2017. Keywords: infrastructure, infrastructure construction, domestic engineering news, planning and investment

The reporter found that during the "Twelfth Five-Year Plan" period, the average annual grid investment of the State Grid and China Southern Power Grid was about 417.6 billion yuan. A number of industry insiders predict that the average annual investment in the two grids during the "14th Five-Year Plan" period will exceed 650 billion yuan. Editor / Xu Shengpeng