Generator Torque in Simulink

Hi there,

I’m using OpenFAST to create custom controllers. I’m doing this through the FAST SFunc block in Simulink, and Gen Tq is one of the inputs.

When obtaining the Gen Tq time history from the out.OutData block, I’ve noticed a large spike in the input at t=0. However, if I try viewing Gen Tq with a Simulink scope block, the spike is not present.

I’ve also noticed this discrepancy with the Gen Tq spike when running both the Simulink example models “OpenLoop.mdl” & “Test01_SIG.mdl”.

Is there any reason why the Gen Tq from out.OutData would be different to the input shown in the Simulink scope (i.e. what Simulink thinks is going into the FAST block)? Any help here would be greatly appreciated.

Thank you!

Dear @Emyr.Williams,

The OpenFAST S-Function will use extrapolated values of the inputs (including generator torque) passed from Simulink (as discussed in other forum topics e.g. S-Function input output signal mismatch). Thus, the OpenFAST S-Function may not report exactly the same values of the generator troque that are input from Simulink.

Best regards,