**5. Conclusions**

This paper is mainly focused on the control of a fault tolerant and reconfigurable grid-connected photovoltaic inverter. The main issue addressed is the possibility to continuously supply critical local load in case of a grid trip event and regardless of the inherent fluctuating nature of the energy generated by PV sources. As a consequence, a suitable islanding detection method is presented and implemented by monitoring the PCC voltage envelope evaluated by means of the Hilbert transform.

A complete set of numerical simulations proved the good performance in normal operation as well as the capability to detect a grid fault event in few milliseconds, thus fully accomplishing the standard requirements. In particular, the minimum time requested to detect the grid outage is equal to 12.5 ms, which can be further reduced to 10 ms in case the grid trip event results in synchronization with the grid period. The proposed IDM appears to be very fast, and it can be compared in terms of speed with respect to different techniques proposed in recent research works, thus showing its benefit in being independent of the specific application.

Moreover, in islanded mode, the system remains fully functional due to a suitable modification of the control strategy, which exploits the integrated *BESS* to continuously provide a flat profile of the load power. Finally, adequate system performance in terms of power quality, power factor, and MPPT efficiency also proves the effectiveness of the proposed control approach.

**Author Contributions:** Conceptualization, D.L., M.C., and P.G.; methodology, D.L., M.C., and P.G.; software, M.C., P.G., and A.D.; validation, M.C., P.G., and A.D.; formal analysis, D.L. and M.C.; investigation, M.C., P.G., and A.D.; resources, D.L., S.D., and A.D.P.; data curation, M.C.; writing—original draft preparation, M.C., P.G., and A.D.P.; writing—review and editing, A.D.P., D.L., S.D., and A.D.; visualization, M.C., P.G., and A.D.; supervision, A.D.P., D.L., and S.D. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

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