Hello！
Recently, I simulated the IEA 15 MW wind turbine with the ROSCO controller using OpenFAST v4.2.1 and v5.0.0, and found distinct differences in control performance.
For the output parameter RtTSR, the average value is about 7.4 in v4.2.1, which is unreasonable. While the average value is around 9.4 in v5.0.0, which conforms well to the rated operating value.
I conducted a cross test: I used the ROSCO .dll file from OpenFAST v4.2.1 in the v5.0.0 case, and the resulting average RtTSR still remained 9.4.
From this test result, I speculate that the difference is not caused by the ROSCO controller itself, but stems from internal mechanism changes between different OpenFAST versions, which leads to different control behaviors of the same controller. I would like to confirm whether my assumption is correct.
Besides, there is another abnormal phenomenon. When running the model in OpenFAST v5.0.0 under turbulent wind and irregular wave conditions, the rotor speed and output power stay completely unchanged throughout the simulation. The power is always fixed at 15 MW without any fluctuation, which is inconsistent with real-world operation characteristics.
I sincerely hope you can help analyze and solve these problems. Thank you very much for your help!
v4.2.1result：
v5.0.0result
Hello！
Recently, I simulated the IEA 15 MW wind turbine with the ROSCO controller using OpenFAST v4.2.1 and v5.0.0, and found distinct differences in control performance.
For the output parameter RtTSR, the average value is about 7.4 in v4.2.1, which is unreasonable. While the average value is around 9.4 in v5.0.0, which conforms well to the rated operating value.
I conducted a cross test: I used the ROSCO .dll file from OpenFAST v4.2.1 in the v5.0.0 case, and the resulting average RtTSR still remained 9.4.
From this test result, I speculate that the difference is not caused by the ROSCO controller itself, but stems from internal mechanism changes between different OpenFAST versions, which leads to different control behaviors of the same controller. I would like to confirm whether my assumption is correct.
Besides, there is another abnormal phenomenon. When running the model in OpenFAST v5.0.0 under turbulent wind and irregular wave conditions, the rotor speed and output power stay completely unchanged throughout the simulation. The power is always fixed at 15 MW without any fluctuation, which is inconsistent with real-world operation characteristics.
I sincerely hope you can help analyze and solve these problems. Thank you very much for your help!
v4.2.1result：
v5.0.0result
