Implementation of Optimal Protection Coordination for Microgrids with Distributed Generations Using Quaternary Protection Scheme

Table 11

Dual-directional primary and backup relay operating times for quaternary scheme in islanded microgrid.

DG operating status	Fault location	Operating times (t) of relay in second; (Rp = primary relay; Rb = backup relay)
		Rp	Rb1	Rb2
Status 1	F-1	R1	R6	R5
		0.172	0.499	0.518
		R2	R3	R4
		0.138	0.522	0.532
	F-2	R3	R2	R1
		0.259	0.532	0.553
		R4	R5	R6
		0.152	0.439	0.461
	F-3	R5	R4	R3
		0.212	0.501	0.505
		R6	R1	R2
		0.196	0.531	0.548
Status 2	F-1	R1	R6	R5
		0.144	0.484	0.497
		R2	R3	R4
		0.540	0.787	0.805
	F-2	R3	R2	R1
		0.309	0.610	0.623
		R4	R5	R6
		0.179	0.465	0.476
	F-3	R5	R4	R3
		0.406	0.715	0.728
		R6	R1	R2
		0.264	0.564	0.578
Status 3	F-1	R1	R6	R5
		0.136	0.432	0.445
		R2	R3	R4
		0.117	0.428	0.443
	F-2	R3	R2	R1
		0.514	0.828	0.837
		R4	R5	R6
		0.219	0.509	0.530
	F-3	R5	R4	R3
		0.296	0.601	0.620
		R6	R1	R2
		0.238	0.548	0.561