Kunliulong UHV hybrid multi-terminal HVDC transmission project was successfully put into operation-NR Electric Co. Ltd

Kunliulong UHV hybrid multi-terminal HVDC transmission project was successfully put into operation

On December 27, 2020, the world's first UHV hybrid multi terminal HVDC transmission project, Kunliulong project, with a number of core equipment provided by NR, was successfully put into operation.

± 800kV Longmen converter station

Kunliulong project is an important project to implement the West to East power transmission and absorb clean energy in China. It is also a major science and technology pilot project in the power industry. The commissioning of the project will further optimize the energy structure of the five southern provincesand help to achieve the goal of carbon peak and neutralization, which is of great strategic significance. Relying on Wudongde Hydropower Station, Kunliulong project will build a new ± 800kV UHVDC transmission line with a total length of 1452km, and three ± 800kV high voltage converter stations in Kunbei, Liuzhouand Longmen. The project will span four provinces, including Yunnan, Guizhou, Guangxi and Guangdong. It will transport green and clean hydropower from Yunnan to Guangxi power load center and Guangdong, Hong Kong and Macao Bay area.

After the project is put into operation, the total transmission capacity will reach 8GW, and 33TWh of clean hydropower will be transmitted annually.

Schematic diagram of Kunliulong Project

Kunliulong project adopts hybrid transmission technology of LCC-HVDC and VSC-HVDC for the first time in the world, which provides valuable experience for the development of world power grid. As the main supplier of Kunliulong project, NR has provided a complete set of core equipment included HVDC control protection system, converter valve, water cooling system, DC measurement, stability control system, DC de-icing and AC protection equipment.

Kunliulong project has many technical challenges and great difficulty in tackling key problems. NR has has successively overcome the coordination of LCC-HVDC and VSC-HVDC, fault self-clearing and high-speed restart of VSC-HVDC overhead line, balance control of VSC-HVDC series valve group, low delay 800kV DC optical current transformer and coordination and cooperation among multi terminal DC stability control systems.

UHV multi terminal Hybrid DC protection & control system

Pole 2 converter valve of Liuzhou station

± 800kV high speed DC optical current transformer

In the process of project construction, NR continued to provide strong support for the construction of kunliulong project. This year, in the face of severe epidemic prevention and control situation, on the basis of strict implementation of epidemic prevention measures, NR accurately and efficiently returned to work and production, completed the production, supply and commission the system on schedule.

Commissioning of stability control system

The commissioning of Kunliulong project marks that the technical level of UHVDC transmission has been upgraded to a new level. As an important participant in the Kunliulong project, NR has fully demonstrated its leading technology level in the field of LCC-HVDC and VSC-HVDC transmission.

NR will continuously develop new technologies and expand new applications, provide customers with advanced technologies, reliable products and high-quality services, and serve the power industry.

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