After setting up the model to collect the frequency response data, in the Simulink model
window, select Analysis > Control Design > Frequency Response Estimation to
begin the estimation process.
To analyze the power factor correction circuit, the frequency response is estimated from a
steady-state operating point. To do so, you create a new operating point from a simulation
snapshot.
In the Linear Analysis Tool, on the Estimation tab, in the Operating Point drop down
list, select Take Simulation Snapshot.
In the Enter snapshot times to linearize dialog box, in the Simulation snapshot times
field, enter 0.15 seconds, which is enough time for the open-loop system to reach steady
state.
Click Take Snapshots.
Design PID Controllers for a Power Factor Corrector using Frequency Response Estimation Method