For more tricks and tweaks, a.k.a. practicalities, for your repetitive process control systems please see our papers:

Krzysztof Jackiewicz, Andrzej Stras, Bartlomiej Ufnalski and Lech Grzesiak, Comparative study of two repetitive process control techniques for a grid-tie converter under distorted grid voltage conditions, International Journal of Electrical Power & Energy Systems (Elsevier), Volume 113, December 2019, Pages 164-175.

https://doi.org/10.1016/j.ijepes.2019.05.003

Andrzej Stras, Bartlomiej Ufnalski, Marek Michalczuk, Andrzej Galecki and Lech Grzesiak, Design of fractional delay repetitive control with a dead-beat compensator for a grid-tied converter under distorted grid voltage conditions, Control Engineering Practice, Volume 98, May 2020.

https://www.sciencedirect.com/science/article/pii/S0967066120300460 (open access)

Acknowledgements: The research was supported by the National Centre for Research and Development (Narodowe Centrum Badan i Rozwoju) within the project No. PBS3/A4/13/2015 entitled Superconducting magnetic energy storage with a power electronic interface for electric power systems (original title: Nadprzewodzacy magazyn energii z interfejsem energoelektronicznym do zastosowan w sieciach dystrybucyjnych), 01.07.2015–31.12.2018. The acronym for the project is NpME.