Innovative design for direct drive and more efficient wind turbines

The starting signal for the BMU-project “lightweight wind turbine direct drive hub generator” has been fired. Researchers from the Fraunhofer IWES and the Wind Energy Research Team (FITT gGmbH) are collaborating on developing a new direct drive 3 MW wind turbine design concept. Future wind turbines (WET) are to be more efficient, more cost-effective and less maintenance intensive. In order to achieve this, it is necessary to make WET drive train changes because if a central component fails through damage long lasting turbine downtimes can occur which in turn lead to wind power production losses. As gearless or direct drive WETs are equipped with fewer components and are therefore less susceptible to damage. This is regarded as the future for wind turbine technology.

A simplified hub generator model was presented at the EWEA 2013 in Vienna, Austria. The exhibit shows a generator to a scale of 1:5 / Source: Fraunhofer IWES

The integrated hub generator of the Fraunhofer IWES and the Wind Energy Research Team (FITT gGmbH) from the Saarland Technical and Business College represents a new gearless drive concept for WET drive trains. Describing the plans, Patrick Tober, Fraunhofer IWES Component and Production Project Leader explains, “material and cost savings are to be achieved through a modular and compact construction as also increased turbine robustness and less damage susceptibility“. The core component of the new concept is its integrated generator construction. The rotor blades are attached directly to the generator and not as previously connected with the hub in front of the nacelle. A lightweight construction is also new solving many logistics problems, as the transport and installation of heavy WET components, especially on the high seas, are very complex and cost intensive issues.

Furthermore, the project will also be examining other innovative aspects such as, for example, fully enclosed or open generator design, reduced component numbers and the cooling system with regards to cost reductions and increased performance. On top of all this, research is being done into how reductions in the mass of the tower head and an integrated lightweight design can be achieved. Another focus of the project is the standardization of components and interfaces, as well as series production possibilities. In future, the hub generator is to be used on direct drive WETs in the output range of 3 MW upwards.

The project “lightweight wind turbine direct drive hub generator” is funded by the German Federal Ministry of the Environment (BMU, code numbers 0325423A and 0325423B). It has a total budget of 1,55 million Euros and runs until December 31st, 2015.

http://www.iwes.fraunhofer.de