ABB Relion 670 series - Page 249

line is introduced. Information about the directional line is given from the directional
element and given to the measuring element as binary coded signal to the input DIRCND.
The zone reach for phase-to-ground fault and phase-to-phase fault is set individually in
polar coordinates.
The impedance is set by the parameters ZPG and ZPP and the corresponding angles by
the parameters ZAngPG and ZAngPP.
Compensation for ground-return path for faults involving ground is done by setting the
parameter KNMag and KNAng where KNMag is the magnitude of the ground-return
path and KNAng is the difference of angles between KNMag and ZPG.
Z0-Z1
3 Z1
KNMag =
×
EQUATION1579 V1 EN (Equation 32)
(
)
0 1
3 1
Z Z
KNAng ang
Z
-
=
×
EQUATION1807-ANSI V1 EN (Equation 33)
where
Z0 is the complex zero sequence impedance of the line in Ω/phase
Z1 is the complex positive sequence impedance of the line in Ω/phase
The phase-to-ground and phase-to-phase measuring loops can be time delayed
individually by setting the parameter tPG and tPP respectively. To release the time
delay, the operation mode for the timers, OpModetPG and OpModetPP, has to be set to
On. This is also the case for instantaneous operation.
The operate timers triggering input can be selected by setting the parameter
ZnTimerSel. The parameter ZnTimerSel can be set to:
• Timers seperated: Phase-to-ground and phase-to-phase timers are triggered by the
respective measuring loop start signals.
• Timers linked: Start of any of the phase-to-ground or phase-to-phase loops will
trigger both the phase-to-ground or phase-to-phase timers.
• Internal start: Phase-to-ground and phase-to-phase timers are triggered by the
INTRNST input.
• Start from PhSel: The phase-to-ground and phase-to-phase timers are triggered by
the DIRCND, STCND, LDCND inputs. Each of the three inputs consist binary
1MRK505222-UUS C Section 6
Impedance protection
243
Technical reference manual