V. Modular Design

90 % of the components used for the AV 928 - 2.5 MW and the AV 1010 – 2.3 MW are identical. This is from the production and supply chain point of view the most cost effective and optimal option, as seperate components can be produced and assembled by different companies worldwide. Furthermore a majority of all parts can be used interchangebly as they are designed for future and larger series, which are currently under development.

Fixed on the base frame of the nacelle, the so-called "king tube", the main shaft, serves both as support for the generator stator and for the central bearings, consisting of an outer cylindrical bearing and an inner double-layer tapered roller bearing. The hub and the spinner as the front part of the drive train are also attached to the king tube. With nearly evenly distributed weights of the rotor blades and the hub on one side, and the generator mass on the other, the mechanical stress on the bearings is relatively small, guaranteeing a long life time of the bearing exceeding that of the turbine. Tests have shown that the loads on the bearings under full load operation are small and the mechanical losses of the system are minimal.

At the entrance to the king tube, the hermetically sealed oil-type transformer is placed directly above the tower, while still allowing enough space for the entrance into the nacelle and from there into the easily accessible hub. The transformer will also be water-cooled in the future versions of the AVANTIS product family, making the nacelle hermetically sealed. The location of the transformer ensures a low level of vibration. In the past, strong vibrations of the nacelle have often destroyed transformers sitting in the back of the nacelle, especially in the case of dry type transformers.

Also, from the location over the tower, the medium voltage power cables are not subject to additional bending in addition to torsion, but can be lead into the tower directly. The internal crane in the back of the nacelle, together with an internal monorail system, allows the hoisting of heavier loads into the nacelle via a hatch in the rear. Fixtures in the spinner are prepared for the hoisting of pitch motors or pitch gearboxes through suitable holes in the spinner. The nacelle cover itself enables overpressure within it, in order to prevent the entrance of dust, sand and ashes. Through a top hatch, the wind speed measurement system, signal lights and telecommunication devices can be accessed. The nacelle also contains suitable fire-fighting equipment and abseiling devices in case of emergency.

The control gear and the converters sit in the middle of the nacelle, on both sides, leaving ample space for maintenance staff. In the back, behind the ladder to the weather station and the hatchet for the crane, the cooling system is conveniently placed in the back of the nacelle cover. It is separated from the inside of the nacelle by a wall, so that during operation no outside air ever enters the nacelle inside.