ABB RELION 670 Series Applications Manual page 350

Section 7
Impedance protection
These settings define the operating direction for Zones Z3, Z4 and Z5 (the directionality of
zones Z1, Z2 and ZRV is fixed). The options are
from respective set value is illustrated in figure
corresponds to the direction out on the protected line.
IEC05000182 V2 EN-US
Figure 213: Directional operating modes of the distance measuring zones 3 to 5
tPPZx , tPEZx , TimerModeZx , ZoneLinkStart and TimerLinksZx
Refer to chapter Simplified logic schemes in Technical Manual for the application of these
settings.
OperationSC
Choose the setting value
with series capacitors. Otherwise maintain the
CVTtype
If possible, the type of capacitive voltage transformer (CVT) that is used for measurement
should be identified. Note that the alternatives are strongly related to the type of ferro-
resonance suppression circuit that is included in the CVT. There are two main choices:
Passive type
Any
None
(Magnetic)
INReleasePE
This setting opens up an opportunity to enable phase-to-earth measurement for phase-to-
phase-earth faults. It determines the level of residual current (3I0) above which phase-to-earth
344
X
R
Non-directional
SeriesComp if the protected line or adjacent lines are compensated
For CVTs that use a non-linear component, like a saturable inductor, to limit overvoltages
(caused by ferro-resonance). This component is practically idle during normal load and fault
conditions, hence the name 'passive'. CVTs that have a high resistive burden to mitigate ferro-
resonance also fall in to this category.
This option is primarily related to the so-called active type CVT, which uses a set of reactive
components to form a filter circuit that essentially attenuates frequencies other than the
nominal in order to restrain the ferro-resonance. The name 'active' refers to the fact that this
circuit is always involved during transient conditions, regardless of voltage level. This option
should also be used for types that do not fall under the other two categories, for example,
CVTs with power electronic damping devices, or if the type cannot be identified at all.
This option should be selected if the voltage transformer is fully magnetic.
Non-directional , Forward or Reverse . The result
213 below, where positive impedance
X
R
Forward
NoSeriesComp setting value.
1MRK 504 152-UEN B
X
R
Reverse
IEC05000182-2-en.vsdx
Application manual