Voltimum Founder Member ABB has launched a new generator for wind turbines based on permanent magnet technology. Compared with a traditional machine, the new generator offers high output relative to the frame size making, for instance, a 3.6 MW unit a ful
The new generator can be operated in a wide speed range with a maximum output of 3.6 MW from a 500mm frame. The efficiency is better than 98%. The design is based on ABB's low speed permanent magnet generator technology, launched last year. This has now been further developed with a more robust rotor suitable for higher speeds.
A better performance overall:
The permanent magnet generator is a synchronous machine where the rotor windings have been replaced with permanent magnets. This eliminates the excitation losses in the rotor, which otherwise typically represent 20 to 30% of the total generator losses. The reduced losses also give a lower temperature rise in the generator, which means that a smaller and simpler cooling system can be used.
The temperature reduction in the rotor also reduces the temperature in the bearings, improving reliability by increasing the lifetime of the bearings and the bearing grease.
The high efficiency of the generator means better utilisation of the wind energy, producing more electrical power. The reduction in size and weight also makes the construction of the windmill easier as smaller lifting equipment can be used.
Better magnet materials:
Recent developments in permanent magnet generator technology have been made possible by a significant improvement of the magnetic materials during the past decade. A piece of neodymium boron iron (NeFeB) material can have a magnetic force more than 10 times stronger than a traditional ferrite magnet.
Contact: Ritva Eskola
ABB Motors
PO Box 633, Stromberg Street 5A,
65320 Vaasa, Finland
Tel: + 358 10 224 1419
Fax: + 358 10 224 7372
Email: [email protected]
Web: www.abb.com