Enable FLORIS to use changing wind direction and thrust control at the same time

[genevievestarke]

Currently, FLORIS only allows either yaw control or thrust control. In Hercules, changing wind directions come across as yaw directions to FLORIS, which means that thrust control is not allowed to be implemented at the same time. This causes an error in the code, currently.

[paulf81]

I think if you used the "mixed" turbine model you can apply both yaw and thurst:

Here's an example where it's used: https://nrel.github.io/floris/examples/examples_control_types/003_setting_yaw_and_disabling.html

[misi9170]

Thanks @paulf81 ! The operation model is already set as "mixed"---I think the issue here is that, although we don't really ever intend to be yaw misaligning and derating at the same time, some instances of that are creeping through (possibly because we are trying to apply "realistic" yaw actions, which don't instantaneously match the wind direction, while also trying to derate). I'll look into this more, and override the yaw actions if that's the case.