Repetitive Controller provides a very low THD in the quantities under control. It exhibits an inherent issue when operated to track variable frequency references. The paper deals with the analysis of the operating conditions when the controller is executed at variable frequency without any resynchronization with respect to the PWM carrier, which is the most common mode of operation. The delays introduced are then evaluated analytically with respect to the sampling frequency and the output frequency to track. The proposed analysis is at the basis of any control tuning and parameters selection.
Faro, A., Lidozzi, A., Di Benedetto, M., Bifaretti, S., Solero, L. (2023). Desynched Operation Analysis of FPGA-based Repetitive Controller in Variable Frequency Domains. In 2023 IEEE Energy Conversion Congress and Exposition, ECCE 2023 (pp.3006-3012). Institute of Electrical and Electronics Engineers Inc. [10.1109/ECCE53617.2023.10362329].