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September 10, 2009, 18:23 
Wind Turbine Transient

#1 
New Member
Sergio Brett
Join Date: Jul 2009
Posts: 14
Rep Power: 8 
Hi all,
I am traying to simulate the transient behaivour of a wind turbine from 0 rpm to operations ones (72 rpm). I want to take into account the torque produce by the blades in order to estimate the rotational speed at the end of each timestep usin the ecuation Wend=((Torque*DeltaT)/inercia momentun)+Wstart I have a problem when I want to assign the Wstart, because and the begining I know that its value is 0, but at the end of each timestep, I need to assign the previus Wend to the new Wstart, in order to estimate the new Wend and so on. I am using cell expressions to define this, but I do not know how to calculate the angular velocity of the previus timestep. If anyone know how to do it, please let me know. Thanks 

September 13, 2009, 23:48 

#2 
New Member
Sergio Brett
Join Date: Jul 2009
Posts: 14
Rep Power: 8 
Hi all,
My problem is I don't know exactly how CEL works. Are the expressions evaluated at the end of each timestep or at the begining?, I did the tutorial of FSI, and I understood that the cel expressions are evaluated at the begining, then according with the results are set the boundary conditions to the next timestep. With this in mind, I wanted to set the new rotation velocity to my turbine for each timestep, using the previus rotation velocity, and I want to calculate this velocity with. areAve(Rotation Velocity)@tip blade / Tip Radius. I used the velocity calculated with this equation with a steady state run, with the rotor rotating at 72 rpm and they have almost the same value. But when I try to use it in the transient run, it calculate a diferent velocity with not physical sense. Could anyone explain to me how the CEL expression works. Thanks 

September 14, 2009, 22:12 

#3  
Senior Member
Steve Hansel
Join Date: Jun 2009
Location: Colorado, USA
Posts: 112
Rep Power: 8 
Quote:


September 14, 2009, 22:37 

#4 
New Member
Sergio Brett
Join Date: Jul 2009
Posts: 14
Rep Power: 8 
Hi hansel.
You are right, the best way to study wind turbines is simulating steady states at diferents spin velocity, but I am studying the transient of a small wind turbine from 0 rpm to operational velocity with constant wind speed. That is why, i need to take into account the inertia of the rotor, the torque generated by the wind and the torque used by the generator. Thanks 

September 14, 2009, 22:38 

#5 
New Member
Sergio Brett
Join Date: Jul 2009
Posts: 14
Rep Power: 8 
Hi hansel.
You are right, the best way to study wind turbines is simulating steady states at diferents spin velocity, but I am studying the transient of a small wind turbine from 0 rpm to operational velocity with constant wind speed. That is why, i need to take into account the inertia of the rotor, the torque generated by the wind and the torque used by the generator. Thanks 

September 15, 2009, 10:20 

#6  
Senior Member
Steve Hansel
Join Date: Jun 2009
Location: Colorado, USA
Posts: 112
Rep Power: 8 
Quote:


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