*Automation and Control*

and robust PSS to the step changes of the mechanical torque and the field excitation voltage, as shown in **Figure 11**. The synchronous generator operates in in the vicinity of the nominal operating point. **Figures 22** and **23** show the generated electrical power, rotor speed, and rotor angle at nominal operating point *P* = 1.0 [pu] and *Q* = 0.62 [pu].

**Figure 24** shows the excitation voltage produced by a robust PSS at operating point *P* = 1.0 [pu] and *Q* = 0.62 [pu]. The limits of the limiters are seen clearly.
