On December 30, 2020, after 168 hours of trial operation, the Qinghai-Henan ± 800kV UHVDC transmission project was officially put into operation.
The Qing-Henan project is the first UHVDC project built for clean energy outsourcing in China. It is an important measure to achieve China's commitment to a carbon peak in 2030 and the carbon-neutral target in 2060.
renewable energy
The project starts in the Hainan Prefecture of Qinghai Province and ends in the Zhumadian area of Henan Province. It passes through Qinghai, Gansu, Shaanxi, and Henan provinces.
The total length of the line is 1587 km and the transmission capacity is 8 GW. After it is fully put into operation, it can transmit 40TWh of green and clean power to Henan every year, which has greatly promoted the development and utilization of renewable energy in the south of Qinghai Province.
core equipment
NR has researched and developed the key technology of the UHVDC transmission application
NR provides a complete set of core equipment for the Qing-Henan project, including an HVDC converter valve, protection & control, valve cooling tower, synchronous condenser secondary system, measurement system, DC voltage divider, stability control system, AC protection, CAFS control system, fire automation, grounding electrode online monitoring, etc.
NR has comprehensively researched and developed the key technology of UHVDC transmission application in high-altitude areas.
UHVDC transmission project
As the only UHVDC transmission project in the world that mainly transports photovoltaic, wind power, and other renewable energy, the overvoltage of power at the sending end will seriously affect the stability of the power grid and limit the transmission capacity of DC.
Aiming at this problem, NR has carried out several special protection & control strategy studies and carried out more than 300 verification tests, which ensured the safety & reliability and made the new strategy become the "centering agent" for the stable operation of Qing-Henan DC project.
third-party verification
Given the special harsh environment of high altitude and severe earthquake magnitude where Qingnan converter station is located, the converter valve system experts have carried out a special project to optimize the design, check the primary and secondary equipment from the main parameters, insulation, heat dissipation, electric field, and other aspects.
All products have passed third-party verification, which provides a solid technical guarantee for the reliable output of renewable energy.
cooling support
The new design reduces the site area and makes maintenance convenient and the service life
The valve cooling system developed by NR provides stable and reliable cooling support for the converter valve. The new design reduces the site area and makes the maintenance convenient and the service life of the equipment long.
NR provides a complete secondary solution for the 4 sets of 300Mvar synchronous condensers, which optimizes and improves the integration of synchronous condenser monitoring and DC protection & control, reactive power coordination control between the condenser and DC protection & control, overcomes the problem of long-distance transmission of renewable energy, significantly improves the convenience of operation and maintenance in the station, and improved the dynamic reactive power support capacity of the condenser.
clean energy
To adapt the flexible operation mode of the AC power grid, aiming at the characteristics of a high proportion of renewable energy in the power grid.
The stability control system adopts the scheme of region, type, and multi-resource collaborative optimization to ensure the delivery and consumption of clean energy to the maximum extent.
multi-disciplinary integration
NR PCS-9119CAFS fire linkage control system can realize the automatic start of the compressed air foam spray and firefighting system in the whole station and the equipment monitoring.
The successful implementation of the Qing-Henan project shows the technical advantages of multi-disciplinary integration and the implementation ability of team cooperation of NR, highlighting the outstanding comprehensive strength of NR in the field of UHV equipment in high altitude and cold regions.
