Circuit Breaker Closed L WT B Circuit Breaker Open Load PV Photovoltaic ICB4 CB4 Utility Grid Wind Turbine Batteries Energy Storage Fault Current Bus 5 ICB7 Bus 6 ICB9 ICB10 CB5 CB7 CB9 CB10 ICB5 PEs Fault ICB6 Backup Protection Main Feeder Protection CB6 CB8 CB11 L L PV ICB2 CB1 CB2 ICB12 CB12 Bus 3 ICB13 ICB15 CB13 CB15 Bus 4 ICB17 ICB18 CB17 CB18 Utility Grid Bus 1 ICB14 Grounding Transformer CB20 ICB3 Bus 2 CB14 CB16 L L WT CB3 Distribution Grid CB19 Microgrid B (a) Circuit Breaker Closed L WT B Load Bus 5 Bus 6 CB5 CB7 CB9 CB10 Circuit Breaker Open PV Photovoltaic CB4 Utility Grid Wind Turbine Batteries Energy Storage Fault Current PEs CB11 CB6 CB8 Fault Main Feeder Protection L L PV CB1 CB2 Bus 3 CB12 Bus 4 CB13 CB15 CB17 CB18 CB14 CB16 CB19 Utility Grid Bus 1 Grounding Transformer Distribution Grid CB20 L Bus 2 CB3 L WT B Microgrid (b) figure 7. (a) A differential protection scheme for microgrids and (b) the operation of the main feeder protection. (Continued) may/june 2021 ieee power & energy magazine 29