The Lagerwey direct drive permanent magnet generator outlines a new era for wind turbine integration. The torque density of our latest generator is very high (compared to conventional direct drive generators) because the magnetic topology uses permanent magnets and a natural air flow based system for cooling the generator. This results in a smaller generator diameter with relatively low mass, because less active material is needed. The generator efficiency is very high -around 97% in both full and partial load- as there is no need for magnetising currents with associated losses. The high partial load performance plays an important role in the overall energy capture performance of the turbine, because it is where the turbine spends the majority of its working life.
The Lagerwey generator design relies on a natural cooling system which uses the natural air flow around the generator to perfectly match its cooling needs. When there is power, there is cooling. The thermal path between the heat source and the cooling fins on the outside is designed to be as short as possible.
Variable Speed and Blade pitch
The Lagerwey variable rotor speed principle with active pitch is designed to follow the optimal aero dynamical working point of the blade at all times. This ensures optimal distribution of the loads at high wind speeds and high energy efficiency at low wind speeds down to 2.2 m/s.
Windings and permanent Magnets
The Lagerwey generator uses form wound coils in the stator which allow for a high filling factor and optimal usage of the slot area. This contributes to a large available cross section in copper and allows for low losses when currents flow through the coils. Low losses means high efficiency and less need for cooling, it cuts both ways. The permanent magnet rotor uses embedded magnets which are coated and encapsulated to protected them from the environment. The stator coils and insulation materials are impregnated with resin to produce a very reliable insulation system with low voltage stress.