Electromagnetic and mechanical optimisation of direct-drive generators for large wind turbines

In terms of drive train technologies, modern wind turbines can be split into two categories: Those with gearboxes between the turbine blades and high speed generator and those with a low speed generator directly-driven by the turbine blades. Direct drive electrical generators typically have large diameters so that they can produce the necessary torque leading to heavier structures. This paper will investigate optimised structures for direct drive generators.