5) The robustness to unmodeled (i.e., higher order) dynamics and to inertia variations is shown to be excellent,
provided that the model inertia is overestimated.
In addition, it is, for tutorial purposes, explicitly shown that 1DOF PI control is unable to give adequate performance.
The message that we hope to convey is that classical-control methods—i.e., 2DOF PI control, pole-placement design, and frequency-domain analysis—are well suited for speed control of electrical drives (although they may erroneously be perceived as obsolete).