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ENERCON E-40 Operating Instructions
Page 10 of 96
Due to the low speed and large diameter of the generator the temperature level during operation is comparatively low and does not fluctuate much. Low temperature fluctuations during operation, low temperatures even at rated power and the avoidance of alternating loads reduce mechanical stresses and the associated ageing of the generator material. In addition, the variable speed reduces speed spikes.
1.3 Rotor
The rotor blades made of fibreglass-reinforced epoxy resin are determining for the yield of the wind energy converter as well as for its sound emission. Shape and profile of the E-40 rotor blades are designed according to the following requirements
high efficiency,
long lifetime,
low sound emission,
low loads
low material consumption.
The E-40 rotor blades are especially designed for the operation with variable pitch and variable speed. Their special profile makes them less susceptible to turbulences and dirt at the leading edge.
The outer surface of the rotor blades is protected against environmental influences by a coating on polyurethane basis. This material is abrasionproof, tenacious and resistant against chemical influence and solar radiation.
The three rotor blades are adjusted via independent microprocessor-controlled pitch control systems. The pitch of the blades is continuously monitored by redundant pitch sensors and then synchronized. This allows for a quick and precise adjustment of the blade angle according to the prevailing wind conditions.
1.4 Yaw control
Directly on the tower a flange plate is mounted. On this tower flange plate the king pin with a geared ring with external toothing is arranged. Two servomotors (yaw drives) engage into the geared ring in order to position the nacelle according to the wind direction. The king pin and the main carrier together form the bearing for the yaw control of the nacelle. The weight of the nacelle is passed on into the tower via two sliding blocks which are fastened to the bottom of the main carrier and supported by the tower flange plate.
Short-time fluctuations of the wind direction lead to dynamic yaw moments which affect the automatic nacelle alignment. The sliding blocks (yaw pads) of the nacelle generate a moment of friction towards the tower axis which is capable of transmitting the dynamic yaw moments into the tower. Sliding blocks and tower flange plate therefore form a so-called friction bearing. Consequently, there is no load acting on the yaw control and its gears while the yaw control is at a standstill.
Short description of the E-40
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