Modifying WP 1.5 MW control strategy for a 2 MW turbine in OpenFAST

[XWQi]

Hello everyone,

I need to urgently build a 2 MW wind turbine model in OpenFAST. I found the documentation of the built-in WP 1.5 MW turbine, which provides blade, tower structural properties, and aerodynamic parameters for both 1.5 MW and 3 MW WP turbines. Based on these two machines, I roughly interpolated a 2 MW turbine in terms of geometry and aero/structural parameters.

However, I am now facing difficulties with the control strategy. My background is mainly in aerodynamics, not control. What I currently have is only the power curve between cut-in and cut-out wind speeds.

I tried modifying pitch.ipt and the generator parameters in WP_VSP_WTurb_ServoDyn, but I do not clearly understand how the parameters in these two files interact. Although changing generator parameters allows the turbine to reach 2 MW rated power, the turbine always enters rated power at 12 m/s, no matter how I tune the parameters.

According to the technical documentation, all WP-series turbines seem to use 12 m/s as the rated wind speed, and I suspect this value is implicitly fixed in the control files. My goal is to make the turbine reach rated power at 16 m/s instead of 12 m/s, but I do not know which control parameters or files should be modified to achieve this.

I would greatly appreciate any guidance or suggestions on how to adjust the control strategy to shift the rated wind speed to 16 m/s.

Thank you very much.

[jjonkman]

Dear @XWQi,

It sounds like you are basing your 2-MW model on the OpenFAST model of the WindPACT (WP) 1.5-MW baseline turbine, which uses torque control from the simple variable-speed torque model in ServoDyn (VSContrl = 1) and pitch control from the sample PitchCntrl_ACH.f90 source file (PCMode = 3 in ServoDyn); is that correct? The simple variable-speed torque controller of ServoDyn is documented in the Variable-Speed Torque Control section of the Controls chapter in the old FAST v6 User's Guide: https://openfast.readthedocs.io/en/main/_downloads/d8bd014121d6505cb25cf49bee5eaa80/Old_FAST6_UsersGuide.pdf. The baseline pitch controller used in the old WindPACT studies is documented in Appendix E of the following report: : https://www.nrel.gov/docs/fy06osti/32495.pdf. Hopefully this documentation provides the information you need.

Alternatively, you could upgrade from this simple and outdated controllers to a more modern reference controller, such as ROSCO: https://github.com/NREL/ROSCO.

Best regards,

[XWQi]

Dear @jjonkman
Thank you very much for your advice! I will carefully read and study the materials you provided. I also sincerely appreciate the valuable contributions you and your team have made to the development of wind energy.