ABB REL670 2.2 IEC Applications Manual page 509

1MRK 506 369-UEN B
Line distance protection REL670 2.2 IEC
Application manual
faulted feeder only. RCADir is set equal to -90° in an isolated network as all
currents are mainly capacitive.
ROADir is Relay Operating Angle. ROADir is identifying a window around the
reference direction in order to detect directionality. ROADir is set in degrees. For
angles differing more than ROADir from RCADir the function is blocked. The
setting can be used to prevent unwanted operation for non-faulted feeders, with
large capacitive earth fault current contributions, due to CT phase angle error.
INCosPhi> is the operate current level for the directional function when OpMode
is set 3I0Cosfi. The setting is given in % of IBase. The setting should be based on
calculation of the active or capacitive earth fault current at required sensitivity of
the protection.
SN> is the operate power level for the directional function when OpMode is set
3I03U0Cosfi. The setting is given in % of SBase. The setting should be based on
calculation of the active or capacitive earth fault residual power at required
sensitivity of the protection.
The input transformer for the Sensitive directional residual over current and power
protection function has the same short circuit capacity as the phase current
transformers. Hence, there is no specific requirement for the external CT core, i.e.
any CT core can be used.
If the time delay for residual power is chosen the delay time is dependent on two
setting parameters. SRef is the reference residual power, given in % of SBase. kSN
is the time multiplier. The time delay will follow the following expression:
×
kSN Sref
=
t
inv j
× ×
3I 3U cos (measured)
0 0
EQUATION1957 V1 EN-US
INDir> is the operate current level for the directional function when OpMode is set
3I0 and fi. The setting is given in % of IBase. The setting should be based on
calculation of the earth fault current at required sensitivity of the protection.
OpINNonDir> is set On to activate the non-directional residual current protection.
INNonDir> is the operate current level for the non-directional function. The setting
is given in % of IBase. This function can be used for detection and clearance of
cross-country faults in a shorter time than for the directional function. The current
setting should be larger than the maximum single-phase residual current on the
protected line.
TimeChar is the selection of time delay characteristic for the non-directional
residual current protection. Definite time delay and different types of inverse time
characteristics are available:
Section 9
Current protection
(Equation 481)
503