ABB RET670 - Page 180

P1
P3
P4
X
R
LineAngle
Z1Fwd
Z1Rev
P2
IEC11000312-2-en.vsd
IEC11000312 V2 EN
Figure 42: Proposed four test points for phase-to-phase fault
Where,
Z1Fwd
is the forward positive sequence impedance setting for zone 1
Z1Rev is the reverse positive sequence impedance setting for zone 1
LineAngle is the Impedance angle for phase-to-phase fault in degrees
Test points X R
P1 Z1Fwd · sin( LineAngle ) Z1Fwd · cos( LineAngle )
P2 (( Z1Fwd - Z1Rev / 2) · sin( LineAngle )) Z1Fwd / 2 · (1 + cos( LineAngle ) + Z1Rev / 2
· (1 – cos( LineAngle ))
P3 (( Z1Fwd - Z1Rev / 2) · sin( LineAngle )) - Z1Fwd / 2 · (1 – cos( LineAngle ) + Z1Rev / 2
· (1 + cos( LineAngle ))
P4 - Z1Rev · sin LineAngle - Z1Rev · cos( LineAngle )
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_Z1 are activated where x refers to the actual phase to be tested. After the trip time
delay for the zone 1 has elapsed, the signals TRIP and TRZ1 shall be activated.
Section 11 1MRK 504 165-UUS -
Testing functionality by secondary injection
174 Transformer protection RET670 2.2 ANSI
Commissioning manual