Normal Stop
The wind turbine will stop if the wind speed is too low or too high to ensure safe operation within a range of wind speeds. To represent a turbine shutdown during normal operation the user can run a normal stop calculation. This will typically involve pitching the blades to feather to stop the rotor from spinning.
Normal stops use aerodynamic braking and/or the shaft brake to stop
the rotor from the normal running condition. For simulations of normal
stops, click the Normal stop button on the Control System screen. To
use the built-in logic for normal stops, specify the following
parameters:
Pitch rate: the constant pitch change rate used during the stop sequence.Final pitch: the final pitch angle. If the Pitch rate is negative, the Maximum pitch should actually be the most negative pitch angle. The initial pitch angle will depend on the running conditions before the stop occurs.Rotor speed for cut-in of shaft brake: when the rotor has slowed down to this value, the shaft brake is applied to bring the rotor to rest.
The normal stop begins at the Time to begin a stop specified in
Simulation control (see 7.13).
Alternatively, click Defined by external controller to use a user-defined controller with normal stop logic . Note that the Time to begin a stop defined in simulation control does not apply in this case.
Note
- Pitch angles and rates apply also to aileron/flap/airbrake deployment angles. They are ignored if the rotor has no aerodynamic control surfaces.
- User-defined supervisory control may also be defined in a user-defined controller.
Last updated 15-11-2024