Hi,

with FAST 8 linearization, the result is four matrices and operational state conditions u_op, x_op, y_op. With these, I am expecting to find

xdot_op = A*x_op + B*u_op

y_op = C*x_op + D*u_op

However, this is not the case:

[code]x_op’ = A*x_op + B*u_op

0.0000

0.0107

x_op’ FAST

1.0e-05 *

```
0.4259
```

-0.9195

y_op = C*x_op + D*u_op

1.0e+03 *

```
0
0
4.8246
```

-0.0825

-0.0005

-0.0006

y_op FAST

1.0e+03 *

-0.0098

-0.0001

5.7420

0.5519

0.0002

0.0003[/code]

I attached my input files, which are the basic 5MW reference turbine with very few degrees of freedom. I use Matlab to structure linearization and linear model. It should be possible to run main.m and reproduce my results (setting FAST8 directory name might be required, but is straight forward).

Where’s the error in my understanding of FAST 8’s linearization?

Thanks,

Tobi

linearization.zip (93.4 KB)