Since 2015, with the construction and operation of a number of ultra-high voltage projects such as the ± 800 kV Qinghai Henan ultra-high voltage direct current project, the great challenges brought by the natural geography and environment of high-altitude areas to the design, research and development, testing and safe operation of the main equipment of ultra-high voltage transmission and transformation projects have been overcome one by one. Among them, State Grid Qinghai Electric Power Research Institute fully leveraged its own advantages and formed a joint research group with various universities, research institutions, and equipment manufacturing enterprises in China to carry out key technologies, equipment, and applications for high-altitude ultra-high voltage transmission and transformation testing in China. After five years of academic research and technological breakthroughs, multiple scientific and technological innovation achievements have been achieved.

The project innovates and independently develops 5 sets of large-scale experimental equipment, which solves the key technologies of low corona field strength, large sample load capacity, and difficult temperature rise control in high-altitude experimental equipment; The high altitude and high voltage laboratory test hall built by State Grid Corporation of China represents the high level of design and construction of high altitude and high voltage experimental halls in China. In addition, we have successively overcome the problem of the impact of environmental factors such as low air pressure in high-altitude areas on the electrical performance of testing equipment, and made every effort to ensure the reliability of testing equipment and conditions in the fully shielded high-voltage testing hall at an altitude of 2500 meters.

According to project experts, the type test of ± 800 kV converter transformers conducted in high-altitude areas and the factory test of six converter transformers in the ± 800 kV Qingyu DC transmission and transformation project have formed a systematic factory test technology for ultra-high voltage converter transformers in high-altitude areas, which strongly supports the construction of the ± 800 kV Qingyu DC transmission and transformation project. It also marks that our province has the ability to conduct ultra-high voltage converter transformer testing at an altitude of 2500 meters, creating a demonstration and model for the development of ultra-high voltage converter transformer testing equipment in high-altitude areas, and a gap in high-altitude verification of ultra-high voltage converter transformers. This has important engineering reference significance for the research and experimental practice of ± 800 kV and ± 1100 kV high-voltage DC engineering testing equipment in high-altitude areas at home and abroad in the future.

In addition, the project has the ability to conduct "double million" external insulation tests for ultra-high voltage in high-altitude areas and type tests for ultra-high voltage converter transformers outside the factory, improving the scientific research system in the field of high sea voltage and creating conditions for maintenance and testing of substation equipment in remote areas. It will effectively enhance the high-quality landing of ultra-high voltage transmission technology in high-altitude areas, support the optimization of clean energy allocation in the western region on a larger scale, and achieve the national goals of "carbon peak and carbon neutrality".