Applying Hybrid PSO to Optimize Directional Overcurrent Relay Coordination in Variable Network Topologies

Table 1

Primary/backup relay pairs and the fault currents in a fixed network topology.

P/B relay pairs		Near-end fault current (A)		Far-end fault current (A)
Primary relay no.	Backup relay no.	Primary relay	Backup relay	Primary relay	Backup relay
1	6	3230	3230	995	995
8	9	6080	1160	2990	553
8	7	6080	1880	2990	78*
2	1	5910	993	3550	393
9	10	2480	2480	1160	1160
2	7	5910	1880	3550	746
3	2	3550	3550	2240	2240
10	11	3880	2340	2480	1140
6	5	6100	1200	3230	626
6	14	6100	1870	3230	78^#
13	8	2980	2980	986	986
14	9	5190	1160	1870	151^#
7	5	5210	1200	1890	181^#
14	1	5190	993	1870	986*
7	13	5210	985	1890	994*
4	3	3780	2240	2400	1050
11	12	3700	3700	2340	2340
5	4	2400	2400	1200	1200
12	13	5890	985	3700	433
12	14	5890	1870	3700	821

^∗Passing through DOCRs fault current flow reverse direction.
^#Passing through DOCRs fault current fall below their pickup current.