A Communication-Assisted Distance Protection for AC Microgrids considering the Fault-Ride-Through Requirements of Distributed Generators

Table 2

Relay operating time (s) during a fault occurring at 12.5% of the feeder AB in the grid-connected mode.

ITA protection relay		Simulation results												Calculation results
		L-G			LL			LL-G			LLL
		Fault resistance (Ω)			Fault resistance (Ω)			Fault resistance (Ω)			Fault resistance (Ω)
		0.01	50	100	0.01	5	10	0.01	50	100	0.01	5	10
Primary protection	1	0.001	0.001	0.001	0.001	0.001	0.001	0.001	0.001	0.001	0.001	0.001	0.001	0.001
	2	0.150	0.153	0.156	0.151	0.151	0.152	0.149	0.151	0.151	0.149	0.149	0.151	0.150
Backup protection	1	0.542	0.544	0.547	0.541	0.542	0.542	0.541	0.541	0.541	0.541	0.542	0.543	0.541
	2	0.572	0.571	0.571	0.573	0.572	0.574	0.572	0.571	0.576	0.572	0.572	0.574	0.573
	4	0.796	0.711	0.676	0.800	0.772	0.752	0.799	0.800	0.800	0.806	0.773	0.753	0.774
	8	—	—	—	—	—	—	—	—	—	—	—	—	—
	9	0.822	0.736	0.698	0.782	0.762	0.746	0.812	0.783	0.782	0.777	0.766	0.750	0.778