Setting Guidelines - ABB REL670 2.2 IEC Applications Manual

1MRK 506 369-UEN B
16.6.3
16.7
16.7.1
Line distance protection REL670 2.2 IEC
Application manual
To overcome the lower dependability in permissive schemes, an unblocking
function can be used. Use this function at older, less reliable, power line carrier
(PLC) communication, where the signal has to be sent through the primary fault.
The unblocking function uses a guard signal CRG, which must always be present,
even when no CR signal is received. The absence of the CRG signal during the
security time is used as a CR signal. This also enables a permissive scheme to
operate when the line fault blocks the signal transmission. Set the tSecurity to 35
ms.

Setting guidelines

The parameters for the scheme communication logic for residual overcurrent
protection function are set via the local HMI or PCM600.
The following settings can be done for the scheme communication logic for
residual overcurrent protection function:
Operation: Off or On.
SchemeType: This parameter can be set to Off , Intertrip, Permissive UR,
Permissive OR or Blocking.
tCoord: Delay time for trip from ECPSCH function. For Permissive under/
overreaching schemes, this timer shall be set to at least 20 ms plus maximum reset
time of the communication channel as a security margin. For Blocking scheme, the
setting should be > maximum signal transmission time +10 ms.
Unblock: Select Off if unblocking scheme with no alarm for loss of guard is used.
Set to Restart if unblocking scheme with alarm for loss of guard is used.
tSendMin: Time duration, the carrier send signal is prolonged.
tSecurity: The absence of CRG signal for a time duration of tSecurity is considered
as CR signal.
Current reversal and weak-end infeed logic for
residual overcurrent protection ECRWPSCH
Identification
Function description
Current reversal and weak-end infeed
logic for residual overcurrent protection
Scheme communication
IEC 61850 IEC 60617
identification identification
ECRWPSCH -
Section 16
M13920-4 v7
IP14365-1 v4
M14883-1 v2
ANSI/IEEE C37.2
device number
85
723