## Simulation of an offshore Wind turbine 5MW based DFIG

This forum if for discussing controls. Questions about how to implement controls in FAST are more appropriate to the CAE Tools forum.

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Ali.Elyaakoubi
Posts: 94
Joined: Wed Oct 21, 2015 8:43 am
Location: MOROCCO

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Thank you the problem is solved
Tell me please what is the name of drive train shaft twist angle output from FAST.

Jason.Jonkman
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### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Dear Ali,

The low-speed shaft twist angle is actually not an available output of the ElastoDyn module of FAST v8. But you can calculate the shaft twist by subtracting the azimuth angle on the gearbox-side of the LSS (LSSGagPxa) from the rotor azimuth angle (LSSTipPxa) (just watch out when the angles shift from just below 360 degrees to 0 degrees).

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Ali.Elyaakoubi
Posts: 94
Joined: Wed Oct 21, 2015 8:43 am
Location: MOROCCO

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Thank you
Please what about the output; low shaft speed torque (the name of the output in FASt)

Jason.Jonkman
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Location: Boulder, CO
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### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Dear Ali,

RotTorq (or equivalently, LSShftMxa etc.) is the name of the low-speed shaft torque output from the ElastoDyn module of FAST v8. Please see the OutListParameters.xlsx spreadsheet provided with the FAST archive for a complete list of output channels available from the ElastoDyn module.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Ali.Elyaakoubi
Posts: 94
Joined: Wed Oct 21, 2015 8:43 am
Location: MOROCCO

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Mr Jonson
Tell me please what about the twist angle (the difference between the High shaft speed and the low shaft speed angle) in FAST, is that different from the twist angle that you have indicated me in the post Fri Mar 17, 2017 9:15 pm
Tell me also if it is equivalent to the drive train shaft twist angle
Thanks

Jason.Jonkman
Posts: 5445
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Dear Ali,

The twist angle I described above is the only drivetrain twist DOF in the ElastoDyn module of FAST v8.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Ali.Elyaakoubi
Posts: 94
Joined: Wed Oct 21, 2015 8:43 am
Location: MOROCCO

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Dear Jonson
Thank you very soon response
Please I am not familiar with Mlife. I foud it a reliable tool to calculate the loads.
Can you please summarize me how I can obtain the flapwise moment and LSS torque DEL in some steps. I have confused with the multiples documentations

Thanks

Jason.Jonkman
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Location: Boulder, CO
Contact:

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Dear Ali,

When you say that you want to obtain the flapwise moment and LSS torque DEL, what type of DEL do you want? MLife has many options for computing DELs e.g. short-term (i.e. a separate DEL for each FAST output file) or lifetime (weighted based on the wind speed probability distribution); based on a fixed mean, zero mean, or without the Goodman correction; etc.

I suggest looking at Test01.mlif in the CertTest folder of the MLife archive to see an example of how short-term DELs are calculated.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Ali.Elyaakoubi
Posts: 94
Joined: Wed Oct 21, 2015 8:43 am
Location: MOROCCO

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Dear MR Jonson
Thank you very much for the suggestion
I have read the Test but I dont revealed my study case. Realy I dont know what type of DEL correspond to my state. In fact my aim is to test the effect of my controller on the fatigue damage of the drive train and the flapwise moment
Can you please guide me how to conduct this simulation
Sincerely yours

Jason.Jonkman
Posts: 5445
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Dear Ali,

I can't tell you what type of DEL is suitable for your analysis. You should pick an approach and set the related inputs appropriately. If you don't know what type of DEL you want and/or don't know how to set the related inputs, I suggest not computing DELs. Instead, you could use the standard deviation of the loads as a proxy for fatigue.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Ali.Elyaakoubi
Posts: 94
Joined: Wed Oct 21, 2015 8:43 am
Location: MOROCCO

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Dear Mr Jonson

Please i want to create a very fluctuant wind profile with Turbsim, i have changed the intensity turbulence A,B and C, also the IEC turbulence type and almost the profile generated is the same
Can you please explain me how to obtain a very fluctuant model

Sincerely yours

Jason.Jonkman
Posts: 5445
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Dear Ali,

I'm not sure I fully understand what you want to do, but the mean wind speed and mean velocity profile are fixed in TurbSim over the simulation length. It is the variations of the velocity components about this mean profile that fluctuate over the simulation.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Ali.Elyaakoubi
Posts: 94
Joined: Wed Oct 21, 2015 8:43 am
Location: MOROCCO

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Thank you Mr Jonson
WELL understood
I means how to generate a very turbulent wind profile (i.e holistic wind). The profile that i have obtained is a litle smooth

Jason.Jonkman
Posts: 5445
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

Dear Ali,

I'm still not sure I understand what you want to do, but if category "A" turbulence is not as severe as you need, you can always specify your own turbulence intensity via TurbSim input parameter IECturbc.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Ali.Elyaakoubi
Posts: 94
Joined: Wed Oct 21, 2015 8:43 am
Location: MOROCCO

### Re: Simulation of an offshore Wind turbine 5MW based DFIG

For example you can see at the image
Wehn i used the turbulent intensity (B) i obtain the below profile , i have also used turbulence intensity until 40% and always the almost the same profile whereas an author have created the profile in the top of the figure. I have never achieve to generate as that even i change the turbulence intensity, I am wondering if there is an other parameter to change

Thanks
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