ABB Relion 670 Series Commissioning Manual page 166

Section 11
Testing functionality by secondary injection
IEC11000313 V2 EN-US
Figure 46: Proposed four test points for phase-to-earth fault
Where,
ZxFwd
ZxRev
LineAngle
Test points
P1
P2
P3
P4
Change the magnitude and angle of phase-to-phase voltage to achieve impedances at test
points P1, P2, P3 and P4. For each test point, observe that the output signals, START and STZx
are activated (where x is 2 or 3 depending on selected zone). After the operate time delay of
the respective zone has elapsed, also the signals TRIP and TRZx (where x is 2 or 3 depending on
selected zone) shall be activated.
Load encroachment
Load encroachment operates on the same measuring principles as the impedance measuring
zones. Thus, it is necessary to follow the same principles as for distance protection when
performing the secondary injection tests. Measure operating characteristics during constant
current conditions. Keep the injected current as close as possible to the rated value of its
associated input transformer or lower. Ensure, however, that it is higher than 30% of the rated
current. Ensure that the maximum continuous current of an IED does not exceed four times Its
160
X
P3
LineAngle
ZxRev
P4
is the forward positive sequence impedance setting for zone x (where, x is 2- 3
depending on the zone selected)
is the reverse positive sequence impedance setting for zone x (where x is 2- 3
depending on the zone selected)
is the Impedance angle for phase-to-phase fault in degrees
X
ZxFwd · sin( LineAngle )
ZxFwd - ZxRev / 2) · sin( LineAngle ))
((
ZxFwd - ZxRev / 2) · sin( LineAngle ))
((
ZxRev · sin( LineAngle )
-
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P1
ZxFwd
P2
IEC11000313-1-en.vsd
R
ZxFwd · cos( LineAngle )
ZxFwd / 2 · (1 + cos( LineAngle ) + ZxRev /2 · (1
– cos(
ZxFwd / 2 · (1 – cos( LineAngle ) + ZxRev / 2 ·
-
(1 + cos(
ZxRev · cos( LineAngle )
-
1MRK 504 165-UEN E
R
LineAngle ))
LineAngle ))
GUID-4E0958A9-000E-440F-A880-89B54774AC63 v3
Transformer protection RET670
Commissioning manual