ABB RET670 Commissioning Manual page 175

1MRK 504 165-UEN A
Transformer protection RET670 2.2 IEC
Commissioning manual
Testing functionality by secondary injection
X
P3
Z1Rev
P4
IEC11000312 V2 EN-US
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
Z1Fwd · sin( LineAngle )
P1
Z1Fwd - Z1Rev / 2) · sin( LineAngle ))
P2 ((
Z1Fwd - Z1Rev / 2) · sin( LineAngle ))
P3 ((
Z1Rev · sin LineAngle
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 STZ1 are activated where x refers to the actual phase to be tested.
After the operate time delay for the zone 1 has elapsed, the signals TRIP and TRZ1
shall be activated.
To verify zone 2 and zone 3 mho characteristic, at least two points must be tested.
P1
Z1Fwd
P2
LineAngle
IEC11000312-2-en.vsd
R
Z1Fwd · cos( LineAngle )
Z1Fwd / 2 · (1 + cos( LineAngle ) +
Z1Rev / 2 · (1 – cos( LineAngle ))
Z1Fwd / 2 · (1 – cos( LineAngle ) +
-
Z1Rev / 2 · (1 + cos( LineAngle ))
Z1Rev · cos( LineAngle )
-
Section 11
R
169