Structural robustness assessment of electric machine applications using individual channel analysis and design

Adequate control of three-phase machines, such as induction motors -IMs- and synchronous generators, is of paramount importance for the electric power industry. These are multivariable, non-linear systems. In this paper, the individual channel analysis and design framework is used to formally demonstrate that the electrical subsystems of the IM and of the permanent magnet SG, due to their inherent structural robustness, are the multivariable equivalent to stable, minimum-phase, single-input single-output systems. As a cnsequence, an adequate performance and robustness may be achieved through fixed, stable, minimum-phase, diagonal controllers –justifying the widespread use of control schemes based on fixed, classical linear controllers such as PI