Dear Zhe.Zhang,
Just a couple comments:
- Did you post-process your linear model to convert the states in the rotating frame to the fixed frame and azimuth-average the state matrices? And did you eliminate the rotor-azimuth state from your state-space model (reducing the total states from 26 to 25). See the following forum topic for more information: FAST linearization V7 - #17 by Yanhua.Liu.
- The linear model is only valid for perturbations about the operating point, so, I would not expect that you’d add the operating point values (12.1 rpm and 14.74 degrees) to your inputs and outputs.
Best regards,