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

Table 10

Dual-directional primary and backup relay operating times for quaternary scheme in grid-connected 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
		0.099	0.399	0.410
		R2	R3	R4
		0.163	0.453	0.466
	F-2	R3	R2	R1
		0.139	0.440	0.454
		R4	R5	R6
		0.099	0.408	0.421
	F-3	R5	R4	R3
		0.119	0.425	0.440
		R6	R1	R2
		0.124	0.466	0.475
Status 2	F-1	R1	R6	R5
		0.099	0.405	0.418
		R2	R3	R4
		0.157	0.473	0.492
	F-2	R3	R2	R1
		0.146	0.450	0.463
		R4	R5	R6
		0.099	0.393	0.412
	F-3	R5	R4	R3
		0.099	0.394	0.404
		R6	R1	R2
		0.126	0.580	0.601
Status 3	F-1	R1	R6	R5
		0.104	0.412	0.425
		R2	R3	R4
		0.167	0.468	0.472
	F-2	R3	R2	R1
		0.153	0.461	0.478
		R4	R5	R6
		0.099	0.404	0.417
	F-3	R5	R4	R3
		0.102	0.448	0.466
		R6	R1	R2
		0.129	0.461	0.474