Hi Jason, all,
Just wondering if anyone has compared generator power output for fixed and floating OWTs and could share any findings?
I ran a quick test case as follows:
- IEA 15MW turbine
- Wind speed above rated (16m/s)
- Turbulent wind modelled (TurbSim Kaimal spectrum with NTM normal turbulence model)
- Challenging sea conditions (Hs 9.8m, Tp 14.1s)
- 10 minute simulation
- Fixed (platform motions disabled) and Free cases
Time History
Statistics (ignoring the initial transient period)
Fixed Model
Mean : 15.015
Std : 0.132
Min : 14.56
Max : 15.46
Floating Model
Mean : 15.017
Std : 0.514
Min : 13.33
Max : 16.89
So it looks like the mean power is almost identical in both cases. The floating model shows more fluctuation in peak power and standard deviaiton. Also max power is abut 11% higher than rated power, so this may cause issues for turbine safety, possibly triggering shutdown
I should also stress that I’ve just run one quick test case, I haven’t looked at different wind or wave conditions, or mis-alignment etc.
If anyone has any comments/insights, or can recommend any technical papers to read, it would be interesting to learn more…
Kind regards,
Aengus.