China's first UHV converter station for clean energy transmission: construction is in full swing at an altitude of 3,400 meters

In March, there is no sign of spring at Tara Beach in Gonghe County, Hainan Tibetan Autonomous Prefecture, Qinghai Province, which is 3,400 meters above sea level. The sky is shrouded in a gray haze by wind and sand, and the Sun and Moon Mountains not far away are still covered with ice and snow.

"Liang Pingxian's temperature is 36.6 degrees Celsius, facial recognition is correct, everything is normal, and he can enter the scene."

The picture shows the GIS plant of China's first ultra-high voltage channel converter station for clean energy transmission. Photo by Cao Shiqi

Early in the morning, outside the GIS plant of the Qinghai Hainan ±800 kV Converter Station on Tara Beach, workers who were about to enter the construction site entered the construction area wearing temperature tags after being identified and registered through the facial recognition system.

Outside the Qinghai Hainan ±800 kV converter station, this winding line between the clouds is the first ultra-high voltage channel in China and even in the world that was built specifically for the export of clean energy. The project passes through four provinces, namely Qinghai, Gansu, Shaanxi and Henan. The total length of the line is 1,562.872 kilometers, with a total investment of approximately RMB 22.6 billion.

"In order to prevent and control the epidemic at the source and reduce contact between personnel and the outside world, we set up independent personnel channels on the AC and DC sides of the GIS plant, and accurately control the entry and exit of personnel through temperature measurement and facial recognition systems." said Wu Jianping, manager of the construction project department.

During the special period of epidemic prevention and control, the construction of the converter station has strengthened detail control. In addition to strengthening personnel control, the construction site has set up multiple points for collecting epidemic prevention items, and organized special personnel to carry out disinfection work in batches. At the same time, from an environmental protection perspective, the site is equipped with standardized auxiliary facilities such as temporary homes for workers, fixed and mobile garbage trucks, and mobile toilets.

GIS equipment installation is a key link in the construction of converter stations. In order to ensure that the GIS equipment docking construction meets the environmental cleanliness requirements, "seven-level dust prevention" measures are taken on site. Installation technicians must wear a full set of dust-proof clothing and shoe covers when entering the site, and use air shower rooms, mist cannons and other equipment to remove dust and ensure that the cleanliness of the docking environment reaches the million level.

The Qinghai Hainan ±800 kV converter station GIS plant is 780 meters long and is currently the longest single-structure steel structure plant in China. Walking into the GIS plant, a large crane is transporting GIS busbars and circuit breakers to the docking operation point. On-site bolt tightening, vacuuming and gas injection of assembled equipment are being carried out in an orderly manner, and the construction scene is in full swing.

According to Wu Jianping, the GIS equipment at this station is 760 meters long and is very difficult to install accurately. In addition to the extremely high requirements for installation cleanliness, the installation accuracy of all GIS equipment must be precisely controlled within 2 mm. Since the project resumed, 20 equipment units have been docked, and a total of 684 equipment units have been docked, with an installation rate of 29.1%.

Due to the large temperature difference between day and night and strong wind and sand in the Hainan Tala area of ​​Qinghai, coupled with the long busbar equipment, the axis expansion and displacement during construction was large, increasing the difficulty of construction.

To ensure installation accuracy, on-site construction personnel brainstormed and used total stations and laser line projectors to measure while installing, ensuring the accuracy of the docking axis, eliminating cumulative installation errors caused by temperature differences and processing errors, and ensuring that the installed molding equipment meets the specifications.

"Although affected by the epidemic, the established goal of putting the project into operation on June 30 has not changed. We must strictly control the quality and progress of the project, race against time to seize the construction period, win the battle against the epidemic, and complete the construction tasks with quality and quantity." Wu Jianping said that this is also the common voice of all participants in the project.

At present, the entire station frame hoisting of the Qinghai Hainan ±800 kV converter station has been completed by 100%, the bracket installation has been completed by 95%, and the on-site GIS equipment installation and station power system equipment installation are being organized in an orderly manner. (End)