3.1.5. Disable for Low Rotor Speeds

An additional feature of the controller is a switch-off mechanism for low rotor speeds. The rotor speed signal Ω is filtered using a low pass filter (see Equation (A2)) and compared to a fraction of the minimum rotor speed: *k*off · Ω*Min*. If the filtered rotor speed signal is below this value, then the torque controller shuts down by setting *Qmax* = *Qmin* = 0 Nm. Note that if the turbine rotor speeds up again and the (filtered) rotor signal exceeds the aforementioned limit, then the torque controller is activated again and functions as described above.
