Applying Hybrid PSO to Optimize Directional Overcurrent Relay Coordination in Variable Network Topologies
Table 3
Operation times of primary/backup relay pairs in a fixed network topology (with near-end faults and far-end faults) using the proposed NM-PSO method.
Near-end fault
Far-end fault
Backup relay
Primary relay
Constraint value (sec)
Backup relay
Primary relay
Constraint value (sec)
No.
Operating time (sec)
No.
Operating time (sec)
No.
Operating time (sec)
No.
Operating time (sec)
6
0.2583
1
0.0583
0.2000
6
3.6456
1
0.3792
3.2664
9
0.3337
8
0.1335
0.2002
9
1.8970
8
0.2701
1.6270
7
0.3799
8
0.1335
0.2464
1
0.3800
2
0.1799
0.2001
1
3.3115
2
0.3954
2.9161
10
0.2830
9
0.0830
0.2000
10
0.8607
9
0.3337
0.5270
7
0.3799
2
0.1799
0.2000
7
2.3585
2
0.3954
1.9631
2
0.3954
3
0.1954
0.2000
2
0.9306
3
0.3752
0.5554
11
0.3895
10
0.1895
0.2000
11
1.2643
10
0.2830
0.9813
5
0.3046
6
0.0914
0.2132
5
1.1760
6
0.2583
0.9177
14
0.4390
6
0.0914
0.3476
8
0.2713
13
0.0713
0.2000
8
1.8682
13
0.4391
1.4291
9
0.3337
14
0.1281
0.2056
5
0.3046
7
0.1045
0.2001
1
0.3807
14
0.1281
0.2526
13
0.4391
7
0.1045
0.3346
3
0.3752
4
0.1752
0.2000
3
1.5123
4
0.2949
1.2174
12
0.4316
11
0.2316
0.2000
12
0.9111
11
0.3895
0.5217
4
0.2949
5
0.0949
0.2000
4
0.9170
5
0.3046
0.6124
13
0.4391
12
0.2389
0.2002
13
2.8975
12
0.4316
2.4659
14
0.4390
12
0.2389
0.2000
14
2.0881
12
0.4316
1.6565
×: both the primary protection and the backup protection are unavailable because the current flowing through the DOCRs is either too small or in the wrong direction.
