Dear Jason,
Thank you for the reply. For the Pitch and torque controllers, I use the OpenFAST dll file given that uses a look-up table for the torque control and a gain scheduled PI control for the pitch above the rated speed.
Looking at the pitch, torque, and generator speed as you suggested, the pitch is always 0° for both turbines because the wind speed used is 10m/s, which is below the 3rd region. The torque and generator speed both make sense for the upstream turbine (Turbine 1), as you can see in the green rectangle below. But for the downstream turbine (Turbine 2), I don’t understand why the torque stays constant while the generator speed decreases (red square). I was expecting the generator torque to decrease as well as the generator speed, almost linearly (since we are in regions 1(1/2) and 2 for the NREL 5MW generator torque - generator speed Figure 7.2)
This is the sequence of images before it throws the error: The error happens at the end, so after the wake of the first turbine hits the second one.
Do you have any ideas where the issue may come from ?
Kindest regars
Younes