On December 25, China’s first flexible DC offshore wind power project – Jiangsu rudonghai offshore wind power project, China’s first megawatt offshore wind power project – Guangdong Yangjiang Shaba offshore wind power project, and China’s farthest offshore wind power project – Jiangsu Dafeng h8-2 offshore wind power project were connected to the grid at full capacity. The three projects are invested and constructed by Three Gorges group China Three Gorges Renewables (Group) Co.Ltd(600905) .
break through the difficult problem of complex marine geological conditions in the South China Sea
Yangjiang project is located in the South Sea area of Shaba Town, Yangjiang City, Guangdong Province, with a total installed capacity of 1.7 million KW. A total of 269 offshore wind turbines and 3 offshore booster stations are arranged. The project can provide about 4.7 billion kwh of clean electric energy for Guangdong, Hong Kong and Macao Dawan district every year, meet the annual power consumption of about 2 million households, and reduce about 4 million tons of carbon dioxide every year.
The reporter learned that during the construction of the project, it has overcome the severe epidemic situation, the poor natural environment for construction in the South China Sea, and the difficulty of quality and safety control. During the peak period of project construction, there are more than 110 construction vessels and nearly 2000 construction workers. The construction period of most bid sections from offshore construction to full capacity grid connection of units is less than 20 months.
“The project has overcome the difficulties of huge rush loading pressure and lack of construction resources.” Liu Junfeng, deputy general manager of Zhujiang company, admitted that during the construction process, 26 steel structure manufacturers in China were arranged to ensure the supply progress; With the support of Yangjiang municipal government, the yard wharf is rented to ensure the reserve of large parts, which greatly improves the efficiency of fan hoisting; Dozens of advanced construction and large transport ships at home and abroad are locked to ensure the on-site construction efficiency and winter construction reliability.
The project took the lead in breaking the installation record of 10 wind turbines per ship per month, and completed the installation of 226 wind turbines per year, setting the highest single offshore wind power construction in China. “The project has overcome the difficulties of complex geological conditions and complicated construction organization. The project optimizes the design scheme according to local conditions, responds to complex geological conditions with different foundation forms, innovates and uses up to 8 foundation types, and successfully builds an offshore wind power foundation Museum, creating the most offshore wind power foundation types in China.” Liu Junfeng introduced.
In addition, the project has also achieved the most and the first of many: the installation of the jacket of the most difficult inclined pile embedded rock booster station has been completed; An offshore booster station with the largest single capacity in Asia has been built, and the hoisting of the 3000 ton heaviest offshore wind duct rack has been completed; China’s first offshore wind power project, 500 kV onshore step-up voltage station, has been built, and China’s first high-capacity 3 × 1000mm2 photoelectric composite submarine cable has put into operation the world’s first anti typhoon floating fan.
Rudong offshore wind power –
fill many technical gaps in China’s offshore engineering
China Three Gorges Renewables (Group) Co.Ltd(600905) Liu Bing, general manager of Jiangsu Branch, said at the Three Gorges Yangjiang, Rudong and Dafeng offshore wind power full capacity grid connection video conference held on December 25 that under the superposition of severe epidemic situation of covid-19 pneumonia, unknown difficulty of technological innovation, shortage of construction ship resources and urgent overall construction period of the project, Jiangsu Rudong H6, H10 It is not easy for Jiangsu Dafeng h8-2 three offshore wind power projects to realize full capacity grid connection on time and on point.
It is understood that Jiangsu Rudong project is located in the huangshayang sea area of Rudong County, Jiangsu Province. It is the first offshore wind power project in Asia to adopt flexible direct transmission technology by supporting the construction of two offshore booster stations, an offshore converter station, a DC cable and an onshore converter station. The offshore converter station of Rudong Rouzhi project is organized by the Three Gorges group in conjunction with relevant units of the industrial chain to tackle key scientific research and complete the construction of the first set. It is currently the largest offshore converter station with the largest capacity, the highest voltage level and the largest volume in the world. Its plane area is almost a standard football field and the height is about 15 floors of residential buildings. It is responsible for collecting and exporting the H6 and H6 of the Three Gorges Rudong H10 project (800000 kW in total) and CGN Rudong H8 project (300000 kW) have a total capacity of 1.1 million KW. HVDC transmission mode has small line loss and stable system, which has economic and technical advantages. The main electrical equipment of the converter station adopts domestic brands, which fills many technical gaps in China’s offshore engineering field.
The average annual on grid power generation of the Three Gorges Rudong H6 and H10 projects will reach 2.4 billion kwh, which can meet the normal power demand of about 1 million households in a year. Compared with thermal power of the same scale, the project can reduce carbon dioxide emissions by about 2 million tons per year.
Dafeng offshore wind power –
break through a series of barriers restricting the development of offshore wind power to deep and Far Seas
The longest distance offshore of Jiangsu Dafeng h8-2 project site is more than 80km, with a total installed capacity of 300MW. It is equipped with an onshore centralized control center, an offshore booster station and an offshore high resistance station.
Compared with land, marine meteorological prediction and geological survey are more difficult, offshore wind power construction process is complex and power transmission distance is longer, which puts forward high requirements for industrial technology level and construction resource allocation. According to China Three Gorges Renewables (Group) Co.Ltd(600905) party secretary and Chairman Wang wubin, Dafeng offshore wind power project has broken through a series of barriers restricting the development of offshore wind power to deep and open seas: the length of the applied submarine cable has reached 86.6km, creating the application record of AC submarine cable with the longest distance and the largest diameter in China; In long-distance AC transmission, the capacitance effect of submarine cable will increase the transmission loss. The first application of offshore high impedance station in China can make up for reactive power loss, curb terminal overvoltage level under low load state, improve power generation efficiency and ensure efficient and stable long-distance transmission of offshore wind power; Innovatively apply the 500kV centralized control center with the largest offshore wind power voltage level in China, and promote the application of GIS, voltage transformer and other domestic equipment.
The average annual on grid power generation of Jiangsu Dafeng h8-2 project will reach 900 million kwh, which can meet the normal power demand of about 370000 households in one year. Compared with thermal power of the same scale, the project can reduce carbon dioxide emissions by about 760000 tons per year.
(China Energy News)
