In this test, impedances were selected within various zones of the polygonal relay characteristic and understandably, the tripping times were different as well.
Bearing in mind that the largest zone determines the fault detection characteristic of the relay, for two tested impedances located outside of the Zone 5, as predicted, there was no trip. This means that these impedances are not part of the protected area and that the protection of this relay will not interfere with the protection of another relay protecting that area.
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For other cases there was always a trip within the nominal tripping time of the corresponding zone, increased with time deviation within permissible tolerances. The quickest way to establish which fault impedance belongs to which zone is by its nominal tripping time. From the results summary, it is obvious that the first fault was located within Zone 1 reach (instantaneous trip), following three faults that were part of Zone 2, following another two within the Zone 4 reach, and the next two within Zone 5. Additionally, there is a no trip case for an impedance outside of the protected area, and there are two simulated faults within the Zone 3 (reversed direction zone), another one within the Zone 5, and finally, the last case simulated a fault located outside of the characteristic.
Test Results
Shot Test: Fault Type L1-L2-L3
| Z |
Phi
t nom
t act.
Dev.
ITest
Result
5,808 ?
85,00 °
0,000 s
34,30 ms
34,30 ms
2,000 A
Passed
6,329 ?
80,00 °
350,0 ms
389,8 ms
11,37 %
2,000 A
Passed
6,758 ?
85,00 °
350,0 ms
389,8 ms
11,37 %
2,000 A
Passed
13,53 ?
85,00 °
350,0 ms
383,6 ms
9,6 %
2,000 A
Passed
14,24 ?
85,00 °
700,0 ms
734,2 ms
4,886 %
2,000 A
Passed
21,93 ?
85,00 °
700,0 ms
734,5 ms
4,929 %
2,000 A
Passed
22,89 ?
85,00 °
1,500 s
1,534 s
2,24 %
2,000 A
Passed
22,33 ?
26,43 °
1,500 s
1,534 s
2,253 %
2,000 A
Passed
24,00 ?
24,74 °
no trip
no trip
2,000 A
Passed
659,1 m?
-95,00 °
800,0 ms
819,0 ms
2,375 %
2,000 A
Passed
3,591 ?
-95,00 °
800,0 ms
813,6 ms
1,7 %
2,000 A
Passed
5,204 ?
-95,00 °
1,500 s
1,534 s
2,287 %
2,000 A
Passed
6,387 ?
-95,00 °
no trip
no trip
2,000 A
Passed