Custom below-rated generator torque: lookup table

[mohsamaz]

Hi ROSCO community,
I’m working with ROSCO and would like to replace the below-rated (Region 2) generator torque command with a custom torque schedule/lookup table.

Currently, for VS_ControlMode=1, Region 2 torque uses the standard K·ω² law (optimal torque). For VS_ControlMode=2/3/4, torque comes from TSR-based reference speed and a PI loop.

Question: Is there any built-in support for a user-defined torque lookup table (e.g., GenSpeed→GenTorque or WindSpeed→GenTorque) for below-rated operation?

If not, what’s the preferred implementation approach in ROSCO?

Best regards,

[dzalkind]

Hi,

There is not currently built in support for a user-defined torque lookup table. It is possible, but it hasn't made it's way into the main repo. In one-off projects in the past, I've done it like this

LocalVar%GenTq = interp1d(CntrPar%VS_SpdTq(:,1),CntrPar%VS_SpdTq(:,2),LocalVar%GenSpeedF * RPS2RPM,ErrVar)

The preferred ROSCO torque control approach is to use the WSE to set a speed setpoint, using VS_ControlMode = 2. Option 3 works as well and avoids using the WSE.

You could also use the open loop control and use the wind speed (estimate) as the breakpoint. Then, you'd make a table from wind speed to generator torque.

If we added the functionality to do a speed-torque lookup, this is probably the route I'd take to add it: we'd just add another option to the breakpoint selection (generator speed) and then you could define an open loop control (torque) based on that breakpoint.

I'll add it to the wish list for ROSCO v2.11, but can't promise a delivery date.

I hope this helps!

Best, Dan