Goldwind Science and Technology – Technology Review.
The above article at MIT’s Technology Review introduces the permanent magnet direct drive (PMDD) wind turbines manufactured by Goldwind Global Science and Technology Company, China.
Engineers at Goldwind have developed a design for a direct-drive wind turbine that has fewer components and does away with the need for a gearbox. Fewer moving parts means less chance for mechanical failure, and the company boasts that its direct-drive turbines are operational at least 98 percent of the time. The turbines use permanent magnet generators formed from rare earth metals; China holds most of the world’s supply of these materials, giving Goldwind a competitive advantage over its foreign competitors.
Goldwind is the second-largest wind turbine manufacturer in China and one of the top 10 in the world, with 5.3 gigawatts of wind power installed worldwide at the end of 2009.
Goldwind’s growth has been highly dependent on the booming Chinese wind market, but the company is now aggressively pursuing business in other areas of the world. It won a contract to supply its direct-drive turbines to a 106.5-megawatt wind farm in Illinois, which marks the first time a Chinese company will supply turbines for a wind power project in the United States.The company also recently signed a contract for a project in Ethiopia, its first in Africa.
Challenges and Next Steps:
The company currently has 1.5- and 2.5- megawatt versions of its direct-drive turbine and has invested heavily in the development of 5- and 6-megawatt versions, which it expects to begin producing next year.
According to the company’s website, the turbine turns a permanent magnet synchronous generator, which is then delivered to the grid via AC-DC-AC converters, at the grid’s voltage and frequency. The full power converter provides high level reactive power control, which means that the power converter monitors the grid variables (voltage, frequency, phase lag/lead, etc.) and reacts accordingly.
In 2008, the Xinjiang, Beijing based Chinese company acquired the German firm, Vensys Energy AG, based in Neunkirchen, Germany, which gave them the capability to do cutting edge research in wind turbine technology.
I feel that this is the natural way to go, eliminate the middle man and increase efficiency, i.e., get rid of the mechanical gear systems that waste energy and switch to the trusted and proven magnet+coil technology to provide both control and power generation in one unit. Even the tasks of braking and parking the turbine during heavy winds can be done magnetically using the electromagnetic system. A magnetic clutch may also be provided to enable smooth transfer of motion. The rare-earth magnets may be lighter than others, but if they are installed on the rotor, will provide the mass required for increased moment of inertia, i.e., a flywheel for smoothening out the rotation and storing angular momentum.
This company is now already competing with European and American manufacturers, winning a contract in the US. They will certainly go far with this technology.