The world's largest 18-megawatt offshore direct-drive wind turbine, jointly developed by the Dongfang Electric Corporation (DEC) and China Huaneng Group Co., Ltd. with complete independent intellectual property rights, rolled off the production line at the production base of Dongfang Electric Windpower (Fujian) Co., Ltd., a subsidiary of DEC in Fuqing City, East China's Fujian Province, on Nov 10. It is currently the offshore direct-drive wind turbine with the largest single-unit capacity and the largest impeller diameter to have been produced.
The 18-megawatt offshore direct-drive wind turbine is a new generation offshore wind turbine developed for Class I wind speed areas at sea. The key components of the turbine, such as blades, generators, inverters, and transformers, are all domestically produced, promoting the coordinated development and technological progress of the entire wind power industrial chain.
Independently developed by DEC, the blades of the wind turbine are 126 meters long and feature large-thickness, blunt trailing edge, and high performance. Employing aerodynamic-structural integration design technology and bending-torsion coupling technology, the blades utilize new carbon fiber pultruded plate materials and a new type of main beam structure that takes into account both structural safety and economic efficiency.
The generator uses an ultra-high power density generator and provides high material utilization and economic efficiency. The arrangement of the dual-bearing structure evenly distributes bearing loads, ensuring a strong bearing capacity, high safety and reliability.
The wind turbine adopts an "actively yawing against typhoons strategy and passive typhoon-resistant structure" design, which is capable of withstanding typhoons with wind speeds of 80 meters per second, and is applicable to a wide range of sea areas. It also adopts the E-top electrical solution that solves the problem of the twist cable layout of the yaw system.
The world's largest 18-megawatt offshore direct-drive wind turbine rolls off the production line at the production base of Dongfang Electric Windpower (Fujian) Co., Ltd. in Fuqing City, East China's Fujian Province, on Nov 10. [Photo/sasac.gov.cn]
This wind turbine employs the industry's first domestically produced integrated dual-drive pitch control system, and solves the stranglehold of key core technologies. The dual-drive pitch control system boasts high safety and can effectively improve the pitch load of super-large wind turbines and extend their service life.
The independently developed iPACOM intelligent system by DEC is the first intelligent control based on edge computing technology. It can identify and protect against operating conditions that threaten the safe operation of the turbine in advance. It also automatically optimizes control parameters based on operating environmental conditions to promote optimal power generation efficiency. The system provides real-time tracking and early warning of the health status of key components to extend the service life of critical components.
The impeller diameter of the 18-megawatt offshore direct-drive wind turbine reaches 260 meters, and the wind turbine consists of more than 30,000 components. The center height of the rotor hub is 160 meters, equivalent to the height of a 53-story residential building. The swept area of the blade is more than 53,000 square meters, equivalent to 7.5 standard football fields put together. When the turbine operates at full capacity, a single unit can generate 38 kilowatt-hours of electricity from just one revolution. With an annual average wind speed of 10 meters per second, a single turbine can generate 72 million kilowatt-hours of clean energy each year, meeting the annual electricity needs of 40,000 households. This can save more than 20,000 tons of standard coal and reduce carbon dioxide emissions by over 55,000 tons.
For offshore wind turbines with a capacity of 10 megawatts or more that have been put into operation nationwide, DEC has already occupied more than one-third of the market. The 10-megawatt offshore wind turbines have been in stable operation for over three years, since being commissioned back in July 2020, and they are the large-capacity offshore wind turbines with the longest operating time, most stability, and of the highest availability in China. The 18-megawatt offshore direct-drive wind turbines, based on the 10-megawatt wind turbine model, have adopted a platform design and give full play to the advantages of DEC's permanent magnet direct drive and full power conversion technologies. It is an upgraded new generation of main offshore wind turbine models with superior grid-connected performance, higher reliability, and lower electricity costs.
The 18-megawatt wind turbine is expected to be mass-produced and will be installed in coastal Class I wind speed areas in China's southeastern coastal areas, offering clean energy to thousands of households.
(Executive editor: Xie Yunxiao)
