Alstom and Converteam Team up on the World's Largest Direct Drive Permanent Magnet Generator for Offshore Wind Power



Global leader in power generation equipment and services, Alstom, and power conversion specialist, Converteam, are collaborating on the world's largest direct drive permanent magnet generator (PMG) for a wind turbine. As a first step Converteam will equip Alstom's two 6 MW offshore wind turbine prototypes that will be installed onshore and offshore in Europe during winter 2011 and in 2012. Alstom's next generation 6 MW turbine combines leading edge, quality technologies into a robust, simple and efficient turbine design that will bring down the cost of energy (COE) of offshore wind. These include an innovative arrangement featuring Alstom's unique and proven ALSTOM PURE TORQUE™ technology and Converteam's world-leading direct drive PMG that will together ensure outstanding reliability of the turbine's drive train. ALSTOM PURE TORQUE™ protects and improves generator performance by diverting unwanted stresses from the wind safely to the turbine's tower. Only turning force, or torque, is transmitted to the generator, which ensures sufficient air gap is maintained between the generator rotor and stator, thereby boosting its performance and reliability. "Direct drive" systems have no mechanical gearbox coupled to the generator. Their low number of rotating parts increases reliability, to maximise turbine availability and reduce maintenance costs. The use of a "permanent magnet" generator leads to better generation efficiencies and even greater overall mechanical reliability, which is critical in offshore wind where reliability is fundamental. Converteam will supply Alstom with its innovative "Advanced High Density" (AHD) direct drive PMG, which is a more compact and lightweight design compared to earlier generation direct drive systems. Alfonso Faubel, Alstom Power's Wind business Vice President, said: "We're developing a robust, simple and efficient turbine that will lower the COE of offshore wind power. Alstom puts quality first, which is why we're partnering with best in class component manufacturers like Converteam. There can be no design compromises on a power-generating product that will operate in the industry's most challenging environmental conditions." Converteam delivered their first permanent magnet generators for 5 MW wind turbines in 2004, and their first high power (rated 3.7MW) direct drive PMG has been in operation since 2008. With more than 22 GW of wind power converters delivered so far they are the world leader amongst independent manufacturers. Pierre Bastid, CEO of Converteam, said: "We're very proud to be Alstom's partner for this exciting and innovative project. The generator will have the largest torque of any Permanent Magnet Generator built to date, and with this project, we are making a big step in commercializing very large direct drive wind generators. Alstom's turbine will be one of the largest direct drive wind turbines in the wind offshore market, and the largest to feature a Direct Drive Permanent Magnet Generator." Alstom's turbine has been developed for the wind conditions encountered in most offshore locations in Europe, the US and the rest of the world. Two prototypes will be installed in 2011 and 2012, a pre-series in 2013 (the final rollout step before full commercialisation), and series production in 2014. Other key features of the turbine include its very large rotor diameter - using the world's longest turbine blades jointly developed with LM Wind Power - and 6 MW power output for higher energy output. High yield helps offset wind farm investment and operating costs. The turbine's weight has also been optimized to reduce installation and infrastructure costs. In January Alstom and EDF Energies Nouvelles (EDF-EN) announced that, using this turbine, they would bid jointly for projects under the recently launched 3 GW French offshore wind tender. Alstom brings to offshore wind its strength of balance sheet, project management skills and power engineering experience. The company has over 100 years experience building utility-size power projects with world class engineering expertise in turbine technology, and 30 years experience specific to wind turbine design, manufacturing and operation. Alstom Grid, the pioneer and a world leader in AC wind farm connections, also plays an important role with its expertise in all aspects of electrical infrastructure for offshore wind, from full wind farm electrical system and grid integration studies, to the engineering and delivery of offshore and onshore substations with the associated compensation system, ensuring full grid code compliance. Alstom Grid can deliver complete offshore substations including HV substation equipment, offshore platform engineering and construction, installation at sea, alone or with a partner. This allows Alstom to provide its customers with comprehensive support at the various development stages of their wind farm to reduce the cost of electricity. To date, Alstom Grid has delivered or is building offshore substations for over 2.3 GW of wind farms.