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ENERCON E-40 Operating Instructions
Page 60 of 96
6.2.2.1 Pitch control cabinet
The control system in the pitch control cabinet
processes the sensor information from the rotating part relevant for the pitch control
controls the pitch of the blades and
drives the servomotor for the pitch control.
The pitch system also checks the discharge degrees of the batteries of the respective standby power supply and carries out the charging. The battery heating is supplied with power also via the pitch control cabinet. Battery voltage and battery temperature are checked and the charging current is adjusted accordingly.
Moreover, each pitch control cabinet contains a mechanical overspeed switch
(centrifugal switch) which, when activated, changes the pitch control motor over to the standby power supply of the blade so that the blade can be pitched out of the wind. As soon as the emergency pitch control (standby power supply) is activated, the pitch control cabinetes are separated from the pitch system. Supplied with power by the battery cabinetes, the rotor blades are brought into feathered position as quickly as possible. When the rotor blades reach the limit angle, the power supply will be changed back to mains / automatic control mode.
The data supplied by the speed sensor in the slip ring casing are evaluated and used as a basis for calculating the rotor speed and rotor acceleration. Based on these control data, on the absolute blade angle and on the blade angles of the other two rotor blades, the new blade angle to be adjusted is determined. Should a fault occur, this will be reported immediately to the central processor (MPU) in the ground station control cabinet and the necessary measures will be initiated.
Via angle encoders the blade angles adjusted of the three rotor blades are constantly monitored and can be compared by the pitch control systems.
Additionally, the pitch control system monitors all the sensors of the rotor head, such as the temperature of the generator rotor.
6.2.2.2 Battery cabinet
The battery cabinet houses a charge-monitored set of batteries. In an emergency, e.g. power failure or other malfunctions, the rotor blades can be pitched out of the wind by means of these batteries.
6.2.2.3 Relay cabinet
The relay cabinet establishes the electrical connection between pitch control and servomotor or battery, respectively. The relay cabinet contains contactors for changing over the servomotors from battery to normal operation and vice versa.
In order to ensure a synchronous operation of the three pitch control units, the change-over between pitch control unit and standby power supply always is carried out simultaneously for all three blades.
6.2.2.4 Pitch control motor
The rotor blades of the E-40 are rigidly connected to the blade adaptors. These in turn are pivoted by a four-point contact bearing on the blade hub. On the E-40, the
The nacelle (the machine house)
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