What is the "golden idea" of the world's highest voltage transmission project site?

Not long ago, Xinjiang section, Anhui section and Gansu section of Zhundong-Weinan 1 100 kV DC transmission project were successively connected. As a transmission project with the highest voltage level, the largest transmission capacity, the longest transmission distance and the most advanced technology in the world, the construction of this line has encountered unprecedented technical problems, but one by one "golden ideas" have made this "energy artery" steadily advance as planned.

This line, which spans more than half of China, started in June 2065438+2006, with a total investment of 40.7 billion yuan and a total length of 3,324 kilometers, passing through six provinces of Xinjiang, Gansu, Ningxia, Shaanxi, Henan and Anhui. Overlooking the project with a drone, it is like a huge silver power tower, lifting wires with arm thickness, starting from Junggar Basin, crossing Tianshan Mountain, Yellow River and Yangtze River, and reaching southern Anhui.

Aiming at the converter station, the heart of the project, the construction difficulty of 1 100 kV converter station is much higher than other voltage levels, and the technical indexes such as converter capacity and electrical insulation are "approaching the limit", which has refreshed the manufacturing level of related equipment in China.

Xinjiang TBEA Co., Ltd. is one of the equipment suppliers of 1 100 kV converter station, and relevant technicians are trying to solve the world-class problems such as insulation and DC bias caused by voltage rise. At the same time, the project adopts the on-site assembly scheme of 1 100 kV indoor DC field and converter transformer for the first time, which further enhances China's international influence and core competitiveness in the field of power grid technology and electrical equipment manufacturing.

The starting point is difficulty. Xinjiang section of this project is the region with the most diverse topography and complicated climatic conditions. Especially when crossing the Gurbantunggut Desert, the second largest desert in China, it is not a difficult problem to make a 33-story tower with a weight of more than 400 tons stand upright, among which the maintenance of foundation concrete is the key. In the past, the "artificial watering method" used in arid areas was time-consuming and laborious, and it simply didn't work in Gurbantunggut Desert.

In view of this, the "drip irrigation" water-saving technology in agriculture has lit up technicians. According to Jin Yi, deputy manager of the new 1 bid section of this project, this technology not only solves the problem of concrete maintenance, but also solves the problem of water saving in desert areas where water is more expensive than oil. According to the test of technicians, the drip irrigation maintenance technology of concrete in desert area ensures the strength of concrete, and the water consumption is equivalent to one sixth of that of ordinary projects.

Walking along the iron tower to the east of Tianshan Mountain has different construction difficulties. The bid section of more than 60 kilometers is not long, but the saline-alkali corrosion is serious, and the whole journey is in the wind zone of 43 meters per second. According to a related person from State Grid Xinjiang Electric Power Co., Ltd., one of the towers took 45 days to build. In order to make the concrete mixed on the mountain outside 15km not solidify, but solidify within 24 hours after pouring, the construction company also cooperated with scientific research institutes to tackle key scientific and technological problems. Finally, concrete is transported by ropeway by adding new material additives.

Turn your eyes to the natural barrier-the Yangtze River. When this project crosses the Yangtze River, the main span tower is 225.2 meters high, the single base tower weighs 1.259 tons, and the total span is 2900 meters. Tower height, tower weight and span are the highest in the whole line. Technicians have to overcome many difficulties, such as the tension of large cross-section conductor as high as 10 ton, the limited navigation time of the golden waterway of the Yangtze River, the changeable air flow at high altitude on the river surface, and the difficulty of climbing the tower. For this reason, in the crossing project, 900 square mm large cross-section conductor is used for the first time; Innovative application of visual management system and line inspection robot to monitor the progress of the project; Improve the pay-off process and directly shorten the two-day sealing time. On April 15, the Yangtze River long-span section of the project was completed.

In the acceptance stage of the Yellow River section, in the face of the tower's large height, large span and large amount of structural funds, technicians used the drone equipment to cooperate with the personnel on the tower for the first time to carry out the acceptance work in a "open-ground combination" way. For the first time, the maintenance company started a group of UAV "flight controllers" and inserted them in each acceptance team. With the characteristics of flexible and intuitive first perspective, drone+routing personnel take gopro for all-round tracking and inspection.

Golden ideas bring tangible benefits. The quasi-east to southern Anhui 1 100 kV DC transmission project can transmit about 66 billion kWh of electricity to the central and eastern regions every year, reducing coal transportation by more than 30 million tons, and reducing the emission of smoke and dust by 24,000 tons, sulfur dioxide149,000 tons and nitrogen oxides157,000 tons. Compared with the 800 kV DC transmission project, the transmission capacity of100 kV is increased from 6.4 million kilowatts to120,000 kilowatts, the economic transmission distance is increased to 3000-5000 kilometers, and the transmission loss per thousand kilometers is reduced to about 1.5%.