Structural Robustness of Electric Machine Applications using the ICAD Framework
Adequate control of three-phase machines (e.g., induction motors -IMs- and synchronous generators -SGs-) is of paramount importance for the electric power industry. These are multivariable, non-linear systems. In this paper, it is formally demonstrated using the ICAD framework 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 consequence, 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 PIs.