**6. Conclusions**

A multiport scheme with CZSI modules to manage unbalanced power conditions was introduced in this paper. The operation principle of the CZSI was presented as well as the design equations to size CZSI components. An analysis of the multiport operation under unbalanced conditions was given. In this scheme, the CZSI was able to drive power from a PV array to the MF link in a single stage. Buck-boost operation of the CZSI modules is achieved by controlling the shoot-through time. CZSI has

the limitation that it only has the duty cycle as a freedom degree and thus MPPT can only be achieved by manipulating this parameter. However, by operating as a current-fed converter, the CZSI modules can operate at similar voltage levels and managing a wider difference between the current levels which make this converter a feasible alternative for PV applications. Simulation and experimental studies were performed in balanced and unbalanced conditions, confirming that this multiport scheme can manage different power levels form PV arrays on its primary side, at the time it generates isolated and balanced outputs on the secondary ports, making it suitable for multilevel converter applications.

**Author Contributions:** Formal analysis, J.M.S. and V.C.; Investigation, J.M.S. and M.G.G.; Methodology, J.M.S., M.A.B. and J.A.; Project administration, V.C.; Supervision, V.C.; Writing – original draft, J.M.S.; Writing – review & editing, V.C. and J.A. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research work was supported by the project UASLP-TRAFOS SLP 252557. The authors would like to thank The National Council of Science and Technology of Mexico (CONACyT) for the academic scholarship under the gran<sup>t</sup> number 415079.

**Acknowledgments:** The authors acknowledge to the UASLP Electrical Power Quality and Motor Control Laboratory (LABCEECM) staff for technical and material support during experimental stage.

**Conflicts of Interest:** The authors declare no conflicts of interest.
