ABB RET670 Commissioning Manual page 142

Section 10
Testing functionality by secondary injection
IEC11000313 V2 EN-US
Figure 34: 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, PICKUP and PU_Zx are
activated (where x is 2 or 3 depending on selected zone). After the trip 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
136
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 )
P1
ZxFwd
P2
IEC11000313-1-en.vsd
R
R
ZxFwd · cos( LineAngle )
ZxFwd / 2 · (1 + cos( LineAngle ) + ZxRev /2 · (1 –
LineAngle ))
cos(
ZxFwd / 2 · (1 – cos( LineAngle ) + ZxRev / 2 · (1
-
LineAngle ))
+ cos(
- ZxRev · cos( LineAngle )
GUID-4E0958A9-000E-440F-A880-89B54774AC63 v3
Commissioning manual
1MRK 504 154-UUS B