Generator torque value while turbine is going to parked

Wind & Water Controls
#1

Hello everybody,

I have a question.Actually, it is a scenerio. Turbine is in operational region(torque or pitch control region) then we deicided to park it. Then it goes to park position. When it goes to park position, I am not sure about what generator torque value should be. It can be zero(Since we are not producing energy). However, if it is zero, aero torque acts to system itself. There can be acceleration on the system.Because generator torque does not exist anymore.Which procedure should I follow? I am happy to hear that any advice or source about this issue.

Best Regards,
Kaan Ciloglu
Aerospace Engineer

#2

Dear Kaan,

For most utility scale turbines, a “parked” condition refers to the generator offline, blades feathered, and a brake applied to prevent the shaft from rotating. Normally this condition would only happen for maintenance purposes. An “idling” condition is more common, where the generator is offline and the blades are feathered. The generator torque is zero in both cases. Feathering the blades minimizes aerodynamic torque, so, while the rotor may oscillate a bit, it will not spin fast.

Best regards,

#3

Dear Jason,

Firstly, thanks for the terms(“idling” and “parked”). For example, we have 6 m/s wind and no pitch or 15 m/s wind and 6 degrees pitch. To go to idling position blades suddenly start to go to 90 degree pitch (min aero torque occured) and suitable yaw degree.When blades start to motion to go to 90 degree, generator torque goes to zero. That is what I learn from you. Am I right?

Best Regards
Kaan Ciloglu
Aerospace Engineer

#4

Yes, that’s correct.

#5

Dear Jason

Is generator torque value going to zero “directly” or “gradually” when blades start to motion to go 90 degree? Thanks for your interested.

Best Regard
Kaan Ciloglu
Aerospace Engineer

#6

Dear Kaan.

That will depend on what is triggering the shut down e.g. high wind speeds, gusts, loss of load. I’m not an expert on the shut down sequencing.

Best regards,

#7

Hi Jason
We solved the problem. Thanks a lot.

Best Regards
Kaan Ciloglu
Aerospace Engineer