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4
Designing Compensators
Adding Poles to the Compensator
Try adding a complex conjugate compensator pole pair on the root locus plot:
1 Open the right-click menu and select Add and then Complex Pole.
2 Click on the root locus plot region where you would like to add one of the
complex poles.
This figure shows these two steps.
Select Add/Complex Pole in the right-click
menu.
Add the poles by placing the ‘x’ on the Bode
magnitude plot. The SISO Design Tool places
the poles at the location that you mark.
Figure 4-28: Adding a Complex Pair of Poles to the Compensator
Try placing the ‘x’ somewhere to the left of the complex pole pair near the
imaginary axis (the figure above shows a good spot). Once you have added the
complex pair of poles, the LTI Viewer response plots change and both the root
locus and Bode plots display the new poles. This figure shows the SISO Design
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