A New Analytical Design Method of Resonant Controllers in Digital Domain under Robustness Constraints

This paper presents a novel approach to designing resonant controllers in the digital domain under robustness constraints. The basic principle for the controller design is the adequate suppression of disturbances at the process input while preserving the robustness of the closed-loop system. Since, the disturbance is an oscillatory, the proposed design methodology results in a resonant controller at the same resonant frequencies as the oscillatory disturbance. Resonant controllers find widespread application in various industries, including distributed power generation systems, modern voltage source inverter control, multiphase machines, and three-phase drives where harmonics must be attenuated. The efficacy of the proposed design methodology is validated through simulation analyses conducted on several typical industrial process models.